October 28, 2008
Cancer
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Thyroid cancer
Definition
Thyroid cancer develops in your thyroid, a butterfly-shaped gland located at the base of your neck, just below your Adam’s apple. Although your thyroid gland is small, it produces hormones that regulate every aspect of your metabolism, from your heart rate to how quickly you burn calories.
Sometimes you may develop one or more solid or fluid-filled lumps called nodules in your thyroid. Most of these are noncancerous (benign) and cause no symptoms. But a small percentage are cancerous (malignant). Serious complications are possible in thyroid cancer.
The prognosis is often excellent for thyroid cancer. The most common types of thyroid cancer can often be completely removed with surgery. But the important first step is to know the symptoms of thyroid cancer and see your doctor.
Symptoms
Most often, you won’t have signs and symptoms in the early stages of thyroid cancer. But, as the cancer grows, you may experience one or more of the following thyroid cancer symptoms:
- A lump — sometimes growing rapidly — in the front of your neck, just below your Adam’s apple
- Hoarseness or difficulty swallowing
- Trouble breathing
- Swollen lymph nodes, especially in your neck
- Pain in your throat or neck, sometimes spreading up to your ears
Having one or more of these symptoms doesn’t mean you have thyroid cancer. Other conditions — including a benign thyroid nodule, an infection or inflammation of the thyroid gland, and a benign enlargement of the thyroid (goiter) — can cause similar problems, all of which are highly treatable.
Causes
Your thyroid gland is composed of two lobes that resemble the wings of a butterfly separated by a thin section of tissue called the isthmus. The thyroid takes up iodine from the food you eat and uses it to manufacture two main hormones, thyroxine (T-4) and triiodothyronine (T-3). These hormones maintain the rate at which your body uses fats and carbohydrates, help control your body temperature, influence your heart rate and regulate the production of protein. Your thyroid gland also produces calcitonin, a hormone that regulates the amount of calcium in your blood.
The thyroid contains two main types of cells. Follicle cells make the thyroid protein thyroglobulin and produce and store thyroxine and triiodothyronine. Other cells, called C cells (parafollicular cells), produce calcitonin. The distinction is important because each type can give rise to different types of cancer.
Papillary and follicular cancers develop in follicle cells. They account for the great majority of thyroid cancers, can usually be completely removed with surgery and generally result in an excellent prognosis. Medullary cancer, on the other hand, arises in the thyroid’s C cells and is generally more aggressive and harder to treat than papillary and follicular cancers are.
The types of thyroid cancer include:
- Papillary cancer
- Follicular cancer
- Medullary cancer
- Anaplastic cancer
- Thyroid lymphoma
Papillary cancer (papillary carcinoma, papillary adenocarcinoma)
This is the most common type of thyroid cancer. It develops from thyroid follicle cells and usually appears as a single mass in one lobe of the thyroid. Anyone, including children, can develop papillary cancer, but it’s most common in women who are between 30 and 50 years of age.
Although most papillary cancers grow slowly, they often spread to the lymph nodes early in the course of the disease. This usually doesn’t affect the outlook for recovery, which is generally excellent when the cancer is small and its spread limited to the lymph nodes in your neck. The prognosis isn’t as positive for people with very large tumors or in the rare cases when papillary cancer has invaded tissues other than the lymph nodes. But even papillary tumors that have spread to the lungs or bone often can be successfully treated with radioactive iodine (radioiodine).
Follicular cancer (follicular carcinoma, follicular adenocarcinoma)
This type of cancer is more aggressive and affects a slightly older population than does papillary cancer. Follicular tumors don’t usually spread to the lymph nodes but are likely to invade the veins and arteries within the thyroid. From there, they may spread to organs such as your lungs and bone.
Medullary cancer (medullary carcinoma)
Rather than arising from follicle cells, this type of thyroid cancer develops in calcitonin-producing C cells. These tumors usually make calcitonin along with carcinoembryonic antigen (CEA) — a protein produced by certain cancers. Both are released into the bloodstream and can be detected by blood tests. But in many cases, medullary cancer may spread to the lymph nodes or other organs before a lump is detected or blood tests show an increase in calcitonin or CEA.
There are three main types of medullary cancer:
- Sporadic. Sporadic tumors make up the great majority of medullary cancers. They primarily affect people between the ages of 40 and 60 and are not inherited.
- Multiple endocrine neoplasia, type II (MEN 2). MEN 2 medullary cancers are passed from one generation to the next and usually appear much earlier in life than do other thyroid cancers. In addition to thyroid tumors, people with MEN 2 usually have tumors in other endocrine glands, such as the adrenal or parathyroid glands. MEN 2 has two subtypes, MEN 2A and MEN 2B.People with MEN 2A often develop adrenal gland tumors (pheochromocytomas) and tumors of the parathyroid glands — four glands that sit behind the thyroid and produce a hormone that helps maintain the proper balance of calcium and phosphorus in the body. Although these associated tumors are usually benign, they can lead to serious complications. Adrenal gland tumors, for example, can cause high blood pressure, and parathyroid tumors can contribute to dangerously high levels of calcium as well as to osteoporosis and kidney stones.People with MEN 2B also have adrenal gland tumors, but not parathyroid gland problems. Instead, they develop benign nerve tissue growths (neuromas), mainly on their tongues, the underside of their eyelids and in the intestines. They may also have thick lips and thickened eyelids. The thyroid cancer that occurs in people with MEN 2B syndrome is particularly aggressive and usually develops at a very young age.
- Familial. Familial medullary cancers are inherited, but unlike MEN 2 cancers, affect only the thyroid gland. They are usually slower growing than MEN 2 tumors, and they primarily affect people who are in their 40s and 50s.
Anaplastic cancer (anaplastic carcinoma)
This rare form of thyroid cancer is sometimes called undifferentiated cancer because it looks very different from normal thyroid tissue under a microscope. It appears to develop from an existing, undiagnosed papillary or follicular cancer. Anaplastic cancer is extremely aggressive, spreads rapidly to the lymph nodes and trachea, and then to other organs, especially the lungs and bone. For that reason, it’s often not curable surgically by the time it’s diagnosed. Unfortunately, other therapies, such as radiation, aren’t usually successful in controlling anaplastic cancer.
Thyroid lymphoma
This rare type of cancer doesn’t develop from thyroid follicular cells or C cells. Instead, it starts in immune system cells called lymphocytes. Although most lymphomas begin in the lymph nodes, some occasionally appear in other organs, such as the thyroid.
What causes thyroid cancer?
Healthy cells grow and divide in an orderly way. This process is controlled by DNA — the genetic material that contains the instructions for every chemical process in your body. When DNA is damaged or altered, changes occur in these instructions. One result is that cells may begin to grow out of control and eventually form a tumor — a mass of malignant cells.
In the case of thyroid cancer, DNA damage can occur from exposure to environmental contaminants such as radiation, from the aging process or, in medullary cancers, from genetic causes:
Risk factors
Although the exact cause of many cases of thyroid cancer isn’t known, certain factors increase your risk:
- Exposure to radiation. This includes radiation you may have received as a treatment for acne or other childhood diseases as well as radiation from nuclear fallout. If you’re concerned about possible radiation exposure, talk to your doctor. Or contact the National Cancer Institute’s Cancer Information Service at (800) 4-CANCER, or (800) 422-6237, for more information.
- Family history. Having a parent with MEN 2A, MEN 2B or familial medullary cancer means you have a 50 percent chance of having the genetic mutation that causes these diseases. If you have one of these types of cancer yourself, your children have a 50 percent chance of developing cancer. Your doctor or a genetic counselor can give you more information and answer any questions you may have regarding genetic screening and treatment.
- Certain inherited conditions. Your risk of papillary thyroid cancer increases if you have Gardner’s syndrome or familial adenomatous polyposis — genetic disorders in which large numbers of precancerous polyps develop throughout your colon and upper intestine. Untreated, Gardner’s syndrome and familial adenomatous polyposis usually lead to colon cancer. Having Cowden disease, a rare, inherited disorder that causes lesions on your face, hands and feet, and inside your mouth, also increases your risk of developing thyroid cancer and breast cancer.
- Your sex. For reasons that aren’t clear, women are two to three times as likely as men to develop thyroid cancer.
- Reproductive history. Women whose last pregnancy occurs at age 30 or later appear to be at higher risk of thyroid cancer than are women who have children earlier in life.
- Age. Papillary and follicular thyroid cancers can develop at any age but are more common in young adulthood. Sporadic medullary thyroid cancer usually occurs in adults. MEN 2 and familial medullary cancer also occur in adults but can affect children and infants as well.
- Race. White Americans are more likely to develop thyroid cancer than black Americans are.
When to seek medical advice
See your doctor if you develop any of the symptoms of thyroid cancer, including a lump in your neck near your Adam’s apple, hoarseness, or trouble swallowing or breathing. And don’t hesitate to talk to your doctor if you think you may be at risk of thyroid problems or are worried about radiation treatments you received in childhood.
Tests and diagnosis
Although it’s possible that you may see or feel a lump (nodule) in your thyroid yourself — usually just to the lower right or left of your Adam’s apple — it’s more likely that your doctor will discover a lump during a routine medical exam. You’re usually asked to swallow while your doctor examines your thyroid because the thyroid moves up and down during swallowing, making nodules easier to feel.
Sometimes a thyroid nodule is detected as an incidental finding when you have an imaging test to evaluate another condition in your head or neck. Nodules detected this way are usually too small to be found during a physical exam.
To aid in diagnosis, you may have one or more of the following tests:
- Ultrasound scan. This imaging technique uses high-frequency sound waves to outline the neck anatomy and detect abnormal growths. While very good at identifying whether a growth or nodule is present, ultrasound scans can’t tell for sure whether it’s malignant or benign. Ultrasound is safe, with virtually no complications associated with its use.
- Fine-needle aspiration (FNA) biopsy. This test is generally considered the most sensitive for distinguishing between benign and malignant thyroid nodules.During the procedure, your doctor places a thin needle through your skin and into a nodule and removes a sample of cells. Several passes are usually needed to obtain tissue from different parts of the nodule. If you have more than one nodule, your doctor is likely to take samples from as many as possible. Often, your doctor will use ultrasound to help guide the placement of the needle. The samples are then sent to a laboratory and analyzed under a microscope.Only a small percentage of biopsied nodules are malignant. This diagnosis is based on the characteristics of individual cells and patterns in clusters of cells that are different from normal thyroid tissue. In some cases, a pathologist can determine specific types of cancer from an FNA biopsy sample.
- Blood tests. If your doctor suspects medullary cancer, you may have tests that check for high levels of calcitonin in your blood. Other tests can provide information about the function of your thyroid gland. For example, you may have a test that measures thyroid-stimulating hormone (TSH), a hormone made by the pituitary gland that regulates thyroid hormones.
Staging tests
If you receive a diagnosis of thyroid cancer, you’re likely to have tests to help determine whether the cancer has spread (metastasized) — a process known as staging. The stage of cancer helps your doctor determine the best course of treatment and the outlook for your recovery. The staging tests you have may vary, depending on the type of thyroid cancer.
Tests such as ultrasonography, computerized tomography (CT) and magnetic resonance imaging (MRI) may help your doctor to see whether the cancer has spread to the lymph nodes or other areas of your neck. Sometimes you may have an octreotide scan — a test that uses a radioactively tagged hormone to check for the spread of medullary cancer.
Screening tests
If you have medullary cancer, consider having DNA testing, which checks a blood sample for the known genetic defects that cause familial and MEN-associated medullary thyroid cancer. A genetic counselor can help determine what a positive or negative test result may mean for your family.
If you have medullary thyroid cancer but don’t test positive for the RET gene, it’s still important that your close family members have their calcitonin levels tested. This is generally done using a calcium infusion test. Although the calcitonin level of healthy people rises slightly after an injection of calcium, it’s much higher in people with medullary thyroid cancer.
The calcium infusion test usually takes between 15 and 20 minutes and is done on an outpatient basis. You’ll have a small amount of blood drawn before the injection of calcium and again at two, five, 10 and 15 minutes after the injection.
Complications
Thyroid tumors can lead to a number of complications, including:
- Difficulty swallowing and breathing. Some thyroid cancers, particularly fast-growing anaplastic tumors and thyroid lymphomas, can cause hoarseness and difficulty breathing or swallowing when they spread to or press on your windpipe or esophagus.
- Hoarseness. The nerves that control your vocal cords lie next to your thyroid gland. Aggressive thyroid cancers can irritate or damage these nerves, leading to a hoarse voice.
- Diarrhea. Medullary thyroid cancer can cause severe diarrhea, which may be related to calcitonin production. It’s usually controlled with drugs that reduce the activity of the intestine, such as Lomotil or Imodium.
- Spread of cancer (metastasis). The most serious complication of thyroid cancer is the spread of the cancer to other tissues and organs. This is especially likely in anaplastic cancer, which has often spread to the windpipe or lungs by the time it’s diagnosed. Follicular and papillary cancers also may spread to distant organs such as the lungs, bone and liver.
Treatments and drugs
Thyroid cancer treatment generally includes one or more of the following:
Surgery
Surgery is the main type of treatment for thyroid cancer. Most surgeons use a procedure called near-total thyroidectomy — an operation that removes practically the entire thyroid with the exception of small rims of tissue around the parathyroid glands to reduce the risk of parathyroid damage. If you have enlarged lymph nodes as a result of thyroid cancer, your operation may be extended to remove the affected lymph nodes.
Cancer is less likely to return or spread after thyroidectomy than after less complete operations, and in experienced hands, the risks of the surgery are low. The greatest risk associated with the operation is unintended nerve injury. Such injury could cause permanent damage to your voice, but this occurs rarely. Another potential risk is damage to the parathyroid glands, resulting in low calcium levels.
In some cases, the type of cancer can’t be diagnosed until the affected tissue is examined. Sometimes, this can be done during surgery using a technique called frozen section, which takes less than 10 minutes to complete and which is performed while you’re still anesthetized. When this procedure isn’t available, surgeons are likely to remove the lobe of the thyroid that contains the nodule (lobectomy) and send it to a pathologist, who examines it under a microscope. If the nodule is malignant, the next step is near-total thyroidectomy.
Thyroid hormone therapy
After any type of surgery for thyroid cancer, you’ll need to take the thyroid hormone medication levothyroxine (Levothroid, Synthroid, others) for life. This has two benefits: It supplies the missing hormone your thyroid would normally produce, and it suppresses the pituitary’s production of TSH, which signals your thyroid to manufacture hormones. High TSH levels could conceivably stimulate any remaining cancer cells to grow.
You’ll likely have blood tests to check your thyroid hormone levels every few months until your doctor finds the proper dosage for you. Too much hormone can cause unintended weight loss, palpitations, tremors, osteoporosis and frequent bowel movements. Too little may lead to weight gain, sensitivity to cold, and dry skin and hair.
Radioactive iodine (radioiodine) follow-up screening and therapy
After surgery, radioiodine may be used in small doses for a follow-up test called a thyroid scan. During the test, a radioactive isotope is injected into the vein on the inside of your elbow. You then lie on a table while a special camera produces an image of your thyroid on a computer screen. The scan can detect any remaining normal thyroid tissue. A thyroid scan also may detect thyroid cancer cells that have spread and that could not be identified at the time of surgery or on other imaging, both in the neck and in other parts of your body.
If any normal tissue remains, moderate doses of radioiodine can be used to eliminate the normal tissue (remnant ablation). Larger doses can be used to destroy any cancerous cells that have spread beyond the thyroid gland. Because radioiodine is taken up primarily by thyroid tissue — including thyroid cancer cells — other parts of your body are less affected. Normal thyroid tissue must be removed first because it absorbs more iodine than do cancer cells, and its presence would make the treatment against cancer cells less effective.
With radioiodine therapy, you take a capsule containing iodine 131. Before you undergo radioiodine therapy, you need high blood levels of TSH in order for cancer cells to take up radioactive iodine. For that reason, you normally discontinue taking thyroid hormones for up to two weeks before therapy or your doctor may recommend a synthetic version of a hormone that artificially elevates blood levels of TSH.
Radioactive iodine therapy is typically administered about six weeks after surgery, generally as an outpatient procedure. Higher doses of this treatment may require hospitalization for two or three days.
You may have a sore throat, nausea and vomiting immediately after radioiodine treatment. You may also have a dry mouth or pain in your cheeks and neck because your salivary glands may absorb some of the radioactive iodine. And because iodine 131 can affect the thyroid gland of a developing fetus or infant, you shouldn’t have radioiodine therapy if you’re pregnant or breastfeeding.
Radioiodine treatments aren’t an option for people with medullary cancer because thyroid C cells don’t absorb iodine.
External beam radiation
Like radioiodine therapy, external beam radiation uses radioactivity to destroy cancer cells. But in this case, the rays come from a source outside your body — a high-energy X-ray machine called a linear accelerator. The cancer cells are targeted with a high dose of radiation for a few minutes at a time, usually five days a week, over the course of six to eight weeks. The goal is to destroy the cancer cells while minimizing damage to healthy tissue. You’re likely to feel very tired later in the course of treatment, and your skin may become red and tender in the treated area, as if you had a bad sunburn. You may also feel hoarse or have trouble swallowing.
Chemotherapy
Chemotherapy, the use of drugs to kill cancer cells that have spread to other parts of the body, may be used in some cases, such as for medullary thyroid cancer, which doesn’t respond to radioiodine therapy. Not every person with medullary thyroid cancer responds to chemotherapy, but in some cases a combination of cancer drugs may shrink tumors or slow their growth.
Chemotherapy may also be used for anaplastic thyroid cancer, the most aggressive and fastest growing type of thyroid cancer. Anaplastic cancer often can’t be helped by surgery by the time it’s diagnosed. Radiation or chemotherapy may shrink tumors slightly and make you more comfortable.
Follow-up care
When the cancer hasn’t spread, the outlook after surgery is excellent. If the cancer has spread to other organs, treatment depends on several factors, including the size of the tumor, how quickly it’s growing, and the extent of the spread. For example, your doctor might choose not to surgically remove a small tumor in the liver, lung or bone. Such tumors sometimes grow slowly for years without causing any symptoms. Large or rapidly growing tumors, on the other hand, may need surgery or other treatment. In that case, you and your doctor will work together to decide on the best type of therapy. Thyroid cancer can recur as many as 20 or 30 years after the original diagnosis, although if you’ve remained cancer-free for five years, the recurrence rate is low.
You’ll likely have periodic blood tests to monitor your level of thyroglobulin, a protein that stores thyroid hormone. Elevated levels of this hormone could indicate that the cancer has returned. You may also have imaging tests, such as ultrasound of the neck or other tests, that help your doctor check for a recurrence of cancer.
Clinical trials
If you have anaplastic cancer, you may want to consider participating in a clinical trial. This is a study that tests new forms of therapy — typically new drugs or surgical procedures, or novel treatments such as gene therapy. Cancer clinical trials are closely monitored to ensure that they’re conducted as safely as possible. And they offer access to treatments that wouldn’t otherwise be available to you. The risk is that treatments used in clinical trials haven’t yet been shown to be effective. They may have serious or unexpected side effects, and there’s no guarantee you’ll benefit from them.
If you’re interested in finding out more about clinical trials, talk to your doctor. You can also call the National Cancer Institute’s Cancer Information Service at 800-4-CANCER, or 800-422-6237. The call is free, and trained specialists are available to answer your questions.
Prevention
It’s often not possible to prevent thyroid cancer. But the following measures may reduce or eliminate your risk:
- Preventive (prophylactic) surgery. If you’ve inherited a defective RET gene, you may choose to have your thyroid gland surgically removed, even though the gland appears to be healthy. This pre-emptive approach eliminates the risk of medullary thyroid cancer but doesn’t reduce the likelihood of adrenal or parathyroid tumors in people with MEN 2 syndrome.
- Potassium iodide tablets. Heightened concerns about national security have focused attention on nuclear power plants in the United States. Current government guidelines recommend that people within 10 miles of these plants be provided with potassium iodide tablets.Taken just before or immediately after exposure to nuclear fallout, potassium iodide protects your thyroid gland from iodine 131, though not from other radioactive material. Children are most at risk from exposure to radioactive iodine, and potassium iodide is safe and effective for even very young children when taken in the proper dosage.Short-term side effects, which are more common in adults than in children, include intestinal problems, allergic reactions and minor rashes. You shouldn’t take potassium iodide if you have multinodular goiter, Graves’ disease or autoimmune thyroiditis.
- A healthy diet. A diet high in fruits and vegetables and low in animal fat can reduce your risk of many types of cancer. The American Cancer Society recommends eating at least five servings of fruits and vegetables every day. They contain antioxidants, which protect your cells from damage that occurs as a result of normal metabolism.In addition, emphasize unsaturated fats (omega-3 fatty acids), especially those found in salmon and other fish, because they may help protect against cancer. Maintaining a healthy weight can also help protect against many diseases, including cancer of the thyroid.
October 28, 2008
Cancer
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Stomach cancer
Definition
Although the incidence of stomach cancer has declined dramatically in the United States and Western Europe in the last 60 years, the disease remains a serious problem in much of the rest of the world, where it’s a leading cause of cancer death.
This global variation is almost certainly linked to two factors that play a major role in the development of stomach cancer — infection with Helicobacter pylori (H. pylori) bacteria and diet, especially the type of diet that’s high in salted, smoked and pickled foods common in areas that lack refrigeration as a means of preserving food.
Stomach cancer is more readily treated when caught early. Unfortunately, by the time stomach cancer causes symptoms, it’s often at an advanced stage and may have spread beyond the stomach. Yet there is encouraging news. You can reduce your risk of stomach cancer by making a few changes in your lifestyle.
Symptoms
One early sign of stomach cancer is microscopic internal bleeding, which is usually only detected by tests that check your stool for blood. You may also feel tired if this bleeding causes the loss of too many healthy red blood cells (anemia). Early stomach cancer may also cause symptoms such as heartburn and abdominal pain, which can be mistaken for other, more common problems.
When the cancer is more advanced, you may experience signs and symptoms such as:
- Discomfort in the upper or middle region of your abdomen that may not be relieved by food or antacids (In the early stages of stomach cancer, pain is often relieved by food or acid-buffering medications.)
- Abdominal discomfort aggravated by eating
- Black, tarry stools
- Vomiting blood
- Vomiting after meals
- Weakness and fatigue
- Unintended weight loss
- Full feeling after meals, even when eating less than normal
Having one or more of these signs and symptoms doesn’t necessarily mean you have stomach cancer. Other more common conditions, especially peptic ulcers, can cause similar problems.
Causes
Your stomach is a muscular sac located in the upper middle of your abdomen, just below your ribs. The stomach walls are lined with three layers of powerful muscles that mix food with enzymes and acids produced by glands in the stomach’s inner lining. Your stomach’s delicate tissues are protected from this acidic mix by a thick, jelly-like mucus that coats the stomach lining.
Types of stomach cancer
- Adenocarcinomas. The great majority of stomach cancers are adenocarcinomas, which start in the glandular cells in the stomach’s innermost lining. Adenocarcinomas account for about 95 percent of all stomach cancers.
- Lymphomas. These are cancers of immune system tissue in the stomach wall. Some lymphomas are aggressive, whereas others grow much more slowly. The latter, known medically as mucosa-associated lymphoid tissue (MALT) lymphomas, usually stem from H. pylori infection and are often curable when found in the early stages.
- Carcinoid tumors. A small percentage of stomach cancers are carcinoid tumors that originate in the stomach’s hormone-producing cells. Carcinoid tumors tend to grow less quickly and spread (metastasize) less frequently than do the more common stomach cancers.
- Gastrointestinal stromal tumors (GISTs). Doctors believe that these rare tumors develop from cells called interstitial cells of Cajal, which are part of your autonomic nervous system. Your autonomic nervous system consists of the nerves that regulate the part of your nervous system that you can’t control, such as your heart rate, blood pressure and intestinal function.Although GISTs can occur anywhere from the esophagus to the rectum, most are found in the stomach. Yet GISTs are not the same as other gastric cancers, differing not only in the cells in which they originate but also in their prognosis and treatment. A majority of GISTs have a specific genetic mutation that allows for treatment with a new form of cancer-specific therapy.
Why stomach cancer develops
Healthy cells grow and divide in an orderly way. This process is controlled by DNA — the genetic material that contains the instructions for every chemical process in your body. Some of the genes in your DNA promote cell division and some slow cell division or program cells to die at the right time. Still other genes control processes that help repair DNA. When DNA is damaged, these genes may not function properly, causing cells to grow out of control and eventually form a tumor — a mass of malignant cells.
Although the causes of many types of cancer aren’t clear, researchers have made progress in pinpointing factors that damage DNA in stomach cells and in understanding how that damage leads to cancer. These factors include:
- H. pylori infection. A majority of the world’s population is infected with corkscrew-shaped bacteria called Helicobacter pylori (H. pylori) that live deep in the mucous layer that coats the lining of the stomach. Although it’s not entirely clear how the bacteria are transmitted, it’s likely they spread from person to person through the oral-fecal route or are ingested in contaminated drinking water. H. pylori infection frequently occurs in childhood and can last throughout life if not treated. It’s the primary cause of stomach ulcers.Having ulcers doesn’t necessarily put you at higher risk of stomach cancer, but having H. pylori infection does. That’s because long-term infection causes inflammation that can lead to precancerous changes in the stomach lining. One of these changes is atrophic gastritis, a condition in which the acid-producing glands are slowly destroyed. It’s likely that low acid levels prevent cancer-causing toxins from being properly broken down or flushed out of your stomach.
- Nitrates and nitrites. These are nitrogen-based chemicals that are added to certain foods, especially cured meats such as ham and bacon, hot dogs and deli meats. Both nitrates and nitrites combine with other nitrogen-containing substances in your stomach to form N-nitroso compounds — carcinogens that are known to cause stomach cancer.
- Salted, smoked or pickled foods and red meat. Before the advent of refrigeration, people commonly preserved food by salting, smoking or pickling. But these foods often contain large amounts of nitrites and nitrates, which can be converted in your stomach into cancer-causing compounds. Countries where consumption of salted meat and fish and pickled vegetables is high — Japan and Korea are notable examples — tend to have correspondingly high rates of stomach cancer. Eating a diet high in red meat, especially when the meat is barbecued or well-done, also has been linked to stomach cancer.
- Tobacco and alcohol use. Tobacco use can irritate the stomach lining, which may help explain why smokers have twice the rate of stomach cancer that nonsmokers do. Alcohol has been associated with an increased risk of stomach cancer, but the link between the two isn’t clear.
Risk factors
Having H. pylori infection makes you more likely to develop stomach cancer than someone who doesn’t have the infection. Even so, most people with H. pylori don’t get stomach cancer, and researchers believe that genetic factors make some people more susceptible to the disease.
Other risk factors for stomach cancer include:
- Your sex. Men have double the rate of stomach cancer that women do.
- Age. Most people who develop stomach cancer are older than 50 years.
- Diet. A diet high in foods preserved by smoking, salting or pickling increases your risk of stomach cancer. So do foods that contain nitrites and nitrates, such as bacon, ham and processed meats. Eating large amounts of red meat — particularly if it’s barbecued or well-done — also increases your risk. On the other hand, consuming plenty of fruits and vegetables, especially those that are red or deep yellow, such as tomatoes, carrots and sweet potatoes, helps protect against stomach cancer.
- Tobacco use. Smokers have twice the incidence of stomach cancers that nonsmokers do.
- Previous stomach surgery. The risk of stomach cancer may increase in people who have had part of their stomach and the opening to the small intestine (pyloric valve) removed — usually as a treatment for peptic ulcers. After stomach surgery, bile and sometimes pancreatic juices can back up, causing irritation and inflammation of the stomach lining (gastritis). In addition, the amount of protective stomach acid decreases while nitrite-producing bacteria may increase. These factors can lead to stomach cancer in some people. In general, the risk is greatest for the first 20 years after the initial surgery.
- Stomach polyps. These are small growths in the lining of your stomach. Most are noncancerous (benign), but adenomatous polyps may be precancerous.
- Familial cancer syndromes. These include hereditary nonpolyposis colon cancer and familial adenomatous polyposis, inherited disorders that slightly increase your risk of stomach cancer. People who carry mutations in the BRCA1 and BRCA2 genes also have an increased stomach cancer risk. These mutations were previously thought to be associated only with breast and ovarian cancers.
- Family history. You’re more likely to develop stomach cancer if you have a parent or sibling with the disease.
- Pernicious anemia. This condition, which is often associated with atrophic gastritis, develops when your stomach is no longer able to make a protein called intrinsic factor that helps your body absorb vitamin B-12. Although pernicious anemia is easily treated with B-12 injections, having the disease can slightly increase your risk of stomach cancer.
- Type A blood. Your blood type is determined by the presence or absence of two proteins — A and B — that occur on red blood cells. For reasons that aren’t clear, people with type A blood have a somewhat higher risk of stomach cancer than do people with other blood types.
- Country of origin. Stomach cancer is more common in some parts of the world — especially Japan, Korea, parts of Eastern Europe, and Latin America — than it is in the United States. These differences are likely related to diet and H. pylori infection. Stomach cancer occurs most often in countries where large amounts of meat or smoked, heavily salted or pickled foods are consumed, or where there is a lack of refrigeration as a means to preserve food.
- Obesity. Extra weight has been associated with an increased risk of some cancers, including stomach cancer.
When to seek medical advice
Stomach cancer is treatable if caught early. Unfortunately, it rarely causes symptoms in the beginning stages. When symptoms do occur, they’re often vague and can easily be mistaken for other, more common but less serious problems such as a stomach virus or heartburn. Less than one in five stomach cancers are diagnosed before they have spread outside the stomach.
See your doctor if you have a persistent feeling of discomfort in the upper or middle region of your abdomen, especially if it occurs in conjunction with fatigue and weight loss.
And see your doctor right away if you develop black, tarry stools or if you vomit after meals. Although not always indicators of stomach cancer, these signs may result from other conditions that require medical care.
Tests and diagnosis
To help diagnose stomach cancer and rule out other possibilities, your doctor may recommend one or more of the following diagnostic tests:
- Upper endoscopy. This procedure allows your doctor to see abnormalities in your upper gastrointestinal (GI) tract that may not be visible on X-rays. For the test, your doctor inserts a thin, flexible, lighted tube (endoscope) through your mouth and into your esophagus, stomach and the first part of your small intestine. Your throat is usually numbed before you’re asked to swallow the endoscope, and you’ll usually receive intravenous medication to ensure that you’re comfortable during the procedure.If any tissue in your upper intestinal tract looks suspicious, your doctor can remove a small sample (biopsy) using instruments inserted through the endoscope. The sample is then sent to a lab for examination by a pathologist.
Upper endoscopy takes about 20 to 30 minutes, although you won’t be sent home until the medication wears off — usually one to two hours later. Risks of the procedure are rare and include bleeding and perforation of the stomach lining. The most common complication is a slight sore throat from swallowing the endoscope.
- Stomach X-ray (barium upper GI series). This test uses a series of X-rays to examine your esophagus, your stomach and the first part of your small intestine.Before the test, you’ll drink a thick liquid (barium) that temporarily coats the lining of your stomach so that it shows up clearly on the X-rays. You may also be asked to swallow a gas-producing liquid or pill, such as sodium bicarbonate, which stretches the stomach and separates its folds, thereby providing a better view of the inner lining.
After the test you can eat normally and resume your usual activities, although you’ll need to drink extra water to help flush the barium from your system. The most common complication of the procedure is temporary constipation.
If you receive a diagnosis of stomach cancer, your doctor is likely to recommend additional tests to help determine the extent of the disease (staging tests) and the best course of treatment. These may include:
- Endoscopic ultrasound. This test helps determine whether cancer has spread into the walls of your stomach or to nearby tissues and lymph nodes. Endoscopic ultrasound is similar to upper endoscopy, but in this case, the endoscope carries a small ultrasound probe that uses high-frequency sound waves to create images of your stomach and surrounding tissues, including lymph nodes.
- Computerized tomography (CT) scan. Used to help check for the spread of cancer outside your stomach — especially to organs such as your liver and lungs — this test uses split-second computer processing and X-ray beams to produce detailed cross-sectional images of your internal organs. A CT scan exposes you to more radiation than conventional X-rays do, but in most cases, the benefits outweigh the risks.
- Magnetic resonance imaging (MRI). This test also looks for the spread of cancer beyond your stomach. But unlike a CT scan, MRI uses a powerful magnetic field and radio waves — not X-rays — to produce cross-sectional images of your body.
- Chest X-ray. This test checks whether cancer has spread to your lungs but isn’t as sensitive as a CT scan.
Treatments and drugs
The kind of treatment you receive for stomach cancer depends on a number of factors, including the location of the cancer, how advanced it is, your overall health and your own preferences. Especially when cancer is advanced, choosing a treatment plan is a major decision, and it’s important to take time to evaluate your choices.
You may also want to consider seeking a second opinion. This can provide additional information to help you feel more certain about the option you’re considering.
The goal of any treatment is always to eliminate the cancer completely. When that isn’t possible, the focus may be on preventing the tumor from growing or causing more harm. In some cases, an approach called palliative care may be best. Palliative care refers to treatment aimed not at removing or slowing the disease, but at helping relieve symptoms and making you as comfortable as possible.
Stomach cancer treatment options include the following:
- Surgery. This is the most common treatment for stomach cancer. Depending on the extent of the cancer, your doctor may remove part (subtotal, or partial, gastrectomy) or all (total gastrectomy) of your stomach as well as some of the surrounding tissue. Lymph nodes near the tumor also are often removed during surgery. After a subtotal gastrectomy, the remaining part of your stomach is connected to your esophagus and your small intestine. If your entire stomach is removed, your surgeon attaches your esophagus directly to your small intestine. A 2006 study suggested that chemotherapy before and after surgery may improve outcomes for certain people, so discuss this with your doctor.When stomach cancer is caught at an early stage and your surgeon is able to remove the entire tumor, a complete recovery is possible. Unfortunately, diagnosis usually doesn’t occur until stomach cancer has spread through the stomach wall to nearby lymph nodes or other organs. At this point, it’s not possible to remove all the cancer surgically, but your doctor may still recommend an operation to alleviate pain, bleeding or obstruction. In some cases of advanced stomach cancer, a laser beam directed through an endoscope can vaporize most of the tumor and relieve obstruction without an operation.
After gastrectomy, some people experience leakage or obstruction where the intestinal tract has been reconstructed. More common problems associated with partial or total gastrectomy include diarrhea, vomiting and dumping syndrome, which occurs when the small intestine fills too quickly with undigested food. Signs and symptoms of dumping may occur immediately after eating (early dumping) or several hours after a meal (late dumping) and include nausea, vomiting, diarrhea, cramping and dizziness.
- Chemotherapy. This treatment uses drugs to help kill cancer cells. Injected into a vein or taken orally, chemotherapy medications travel through your bloodstream and are often used to eliminate cancer cells that may remain after surgery or to treat cancers that have spread to other parts of the body. Chemotherapy may also be used to control cancer growth, prolong life or relieve symptoms of advanced disease. Although it sometimes may be the only treatment needed, doctors most often use chemotherapy in conjunction with other therapies. For example, in locally advanced stomach cancer, which occurs when the tumor affects only the stomach and nearby tissues, chemotherapy and radiation (radiotherapy) may be offered after surgery to help increase survival and improve quality of life.A 2006 study found that people whose stomach cancer hadn’t spread had better outcomes when chemotherapy was used both before and after surgery to remove the cancer. In the study, people with stomach cancer were randomly assigned to receive surgery alone or to receive three cycles of chemotherapy before surgery and three cycles of chemotherapy after recovering from surgery. People in this study who received surgery combined with chemotherapy lived somewhat longer and had a lower risk of the cancer returning than did people who received surgery only.
Because anti-cancer drugs affect healthy cells as well as cancerous ones — especially fast-growing cells in your digestive tract and bone marrow — side effects such as nausea and vomiting, fatigue, and an increased risk of infection due to a shortage of white blood cells are common. Although not everyone experiences these side effects, chemotherapy can sometimes feel like another illness and is often the part of treatment about which people are most apprehensive. But newer anti-nausea medications can prevent or reduce most nausea. Sometimes acupuncture or relaxation techniques, such as guided imagery, meditation and deep breathing, also may help control nausea and vomiting. Chemotherapy is normally administered in cycles, with periods of treatment alternating with periods of recovery during which your body can recover. Ask your treatment team about the side effects of any treatment you’re considering and the best ways to minimize those effects.
- Radiation therapy (radiotherapy). This therapy uses high-energy X-rays to kill cancer cells. Unlike chemotherapy, which affects your entire body, radiation affects only those parts of your body through which the radiation beam passes. Because any tissue touched by radiation can be damaged, doctors are careful to aim the beam in a way that’s least likely to harm healthy tissue. Radiation that comes from a machine outside your body (external beam radiation) is generally used to treat stomach cancer, especially in conjunction with chemotherapy. It may also help relieve pain and blockages. Side effects may include a burn similar to sunburn on your skin where the radiation enters your body, nausea, vomiting, and fatigue that may increase over the course of treatment.
- Antibiotics. Carefully selected individuals who have H. pylori-associated gastric lymphomas may be cured by antibiotic therapy that eliminates the bacteria causing this cancer. If you have this type of cancer, your doctor will need to carefully monitor your condition for recurrence or for the presence of more advanced disease that requires more aggressive therapy.
Targeted drug therapy
The Food and Drug Administration has approved the anti-leukemia drug imatinib mesylate (Gleevec) to treat gastrointestinal stromal tumors (GISTs) that contain a specific genetic mutation. Imatinib, which is taken in capsule form once a day, belongs to a class of medications that target a specific genetic mutation within cancer cells but leave healthy tissue relatively untouched. Side effects tend to be milder than with other types of cancer therapy and include fluid retention (edema), nausea, muscle cramps and rash.
Imatinib is effective only for GISTs that have a specific genetic mutation and even then, it isn’t for everyone — surgical removal remains the primary therapy for this type of cancer. Despite promising results in some people, imatinib isn’t effective in all cases nor are the long-term effects known.
Clinical trials
If you have advanced stomach cancer, you may want to consider participating in a clinical trial. This is a study that’s used to test new forms of therapy — typically new drugs, different approaches to surgery or radiation treatments, and novel methods such as gene therapy. If the therapy being tested proves to be safer or more effective than current treatments, it will become the new standard of care.
The treatments used in clinical trials haven’t yet proved effective. They may have serious or unexpected side effects, and there’s no guarantee you’ll benefit from them.
On the other hand, cancer clinical trials are closely monitored by the federal government to ensure they’re conducted as safely as possible. And they offer access to treatments that wouldn’t otherwise be available to you.
If you’re interested in finding out more about clinical trials, talk to your treatment team. You can also call the National Cancer Institute’s Cancer Information Service at 800-4-CANCER, or 800-422-6237. The call is free and trained specialists are available to answer your questions.
Prevention
Although it may not be possible to prevent stomach cancer, the following steps can help reduce your risk:
- Emphasize fruits and vegetables. A diet rich in fresh fruits and vegetables, especially those high in vitamin C and beta carotene, has been shown to help protect against stomach cancer. Look for deep green and dark yellow or orange fruits and vegetables, such as Swiss chard, bok choy, spinach, cantaloupe, mango, acorn or butternut squash, and sweet potatoes. Also try to eat vegetables from the cabbage family, including broccoli, brussels sprouts and cauliflower. Lycopene, a nutrient found in tomatoes and other red fruits and vegetables such as strawberries and red bell peppers, may be a particularly powerful anti-cancer chemical.
- Avoid nitrites and nitrates. These nitrogen compounds are known to contribute to stomach cancer. They’re found primarily in processed meats — bologna, salami and corned beef, for instance — and in cured meats such as ham and bacon.
- Limit smoked, pickled and heavily salted foods. These have been linked to an increased risk of stomach cancer. Countries where the consumption of smoked, pickled and salted food is high have correspondingly high stomach cancer rates.
- Don’t smoke. Tobacco use greatly increases your risk of stomach cancer, especially cancer that occurs at the junction of the esophagus and stomach.
- Limit alcohol consumption. Alcohol may cause changes in cells that can lead to cancer.
- Limit red meat. Eating large amounts of red meat — particularly when it’s barbecued or well-done — increases your risk of stomach cancer. Instead, choose fish or poultry.
- See your doctor if you have symptoms of an ulcer. Infection with H. pylori, the bacterium that causes most cases of gastric ulcers, is one of the leading causes of stomach cancer. Don’t ignore symptoms of ulcers, such as a gnawing pain in your abdomen or chest that’s worse when your stomach is empty or at night. Other, more severe signs and symptoms of ulcers include nausea, vomiting, bleeding and unintended weight loss.
Lifestyle and home remedies
After gastrectomy, it’s not uncommon to experience nausea, vomiting, diarrhea, weight loss, nutritional deficiencies and dumping syndrome, which occurs when food enters your small intestine too quickly. These side effects usually result from eating more at one time than your digestive system can tolerate and can often be controlled with changes in the amount, frequency and kinds of food you eat.
You may also develop nutritional deficiencies because you’re no longer able to absorb certain vitamins. Vitamin B-12, for example, can only be absorbed when it’s attached to a protein produced in your stomach (intrinsic factor). For that reason, you’ll need to receive vitamin B-12 injections for life. Your doctor may also recommend supplementing your diet with other nutrients, especially folic acid, iron and calcium.
Although coping with the effects of gastrectomy can be challenging, the following measures may help improve or relieve your symptoms:
- Eat small, frequent meals. Normally, your stomach can expand to accommodate what you eat and drink, which it then releases slowly into your small intestine. After gastrectomy, you won’t be able to eat as much at one sitting as you once did, although you likely can consume the same amount overall. To get the calories you need while minimizing intestinal symptoms, try eating six small meals a day, rather than two or three large ones.
- Avoid drinking with meals. Although it’s important to drink plenty of fluids, especially water, drinking with meals hastens the movement of food through the upper part of your digestive tract and may reduce the absorption of nutrients. Instead, try to drink 30 minutes before or 60 minutes after you eat.
- Eat slowly and chew thoroughly. This can help reduce nausea and vomiting and increase your ability to absorb nutrients.
- Avoid extremely hot or cold foods or liquids. These may aggravate your symptoms.
- Rest after meals. It’s best to relax after you eat because activity increases the likelihood of nausea and vomiting. Don’t lie flat, however, for at least two to three hours after a meal.
- Avoid sugar. All forms of sugars and sweets aggravate dumping syndrome.
- Use dairy products cautiously. Some people find that dairy foods such as milk, cheese and even yogurt cause gas, bloating and abdominal pain. In that case, an enzyme product such as Lactaid or Dairy Ease may help break down lactose. Consuming small amounts of milk products or combining them with other foods to slow digestion also may help. In some cases, though, you may need to eliminate dairy foods completely. If so, be sure to get enough protein, calcium and B vitamins from other sources.
- Avoid troublesome foods. If certain foods make your symptoms worse, don’t eat them. Instead, try eating softly cooked or pureed fruits and vegetables, rice, plain baked potatoes, soups, broth, and chicken or fish cooked without fat.
- Talk to a dietitian. It’s difficult to get the calories and nutrition you need on a restricted diet. A dietitian can help you plan healthy meals that don’t aggravate your symptoms.
Coping and support
A diagnosis of cancer can be extremely challenging. Remember that no matter what your concerns or prognosis, you’re not alone. These strategies and resources may make dealing with cancer easier:
- Know what to expect. Find out everything you can about your cancer — the type, stage, your treatment options and their side effects. The more you know, the more active you can be in your own care. In addition to talking with your doctor, look for information in your local library and on the Internet. Representatives from the National Cancer Institute will answer questions from the public. You can reach them at 800-4-CANCER, or 800-422-6237. Or contact the American Cancer Society at 800-ACS-2345, or 800-227-2345.
- Be proactive. Although you may feel tired and discouraged, don’t let others — including your family or your doctor — make important decisions for you. Take an active role in your treatment.
- Maintain a strong support system. Having a support system can help you cope with any issues, pain and anxieties that might occur. Although friends and family can be your best allies, they sometimes may have trouble dealing with your illness. If so, the concern and understanding of a formal support group or others coping with cancer can be especially helpful. Although support groups aren’t for everyone, they can be a good source for practical information. You may also find you develop deep and lasting bonds with people who are going through the same things you are.
- Set reasonable goals. Having goals helps you feel in control and can give you a sense of purpose. But don’t choose goals you can’t possibly reach. You may not be able to work a 40-hour week, for example, but you may be able to work part time. In fact, many people find that continuing to work can be helpful.
- Take time for yourself. Eating well, relaxing and getting enough rest can help combat the stress and fatigue of cancer. Also, plan ahead for the downtimes when you may need to rest more or limit what you do.
- Stay active. Being diagnosed with cancer doesn’t mean you have to stop doing the things you enjoy or normally do. For the most part, if you feel well enough to do something, go ahead and do it. Stay involved as much as you can.
Talking about end-of-life issues
Although it can be extremely difficult, discuss end-of-life issues with your family and medical team. Part of this discussion will likely involve advance directives — a general term for verbal and written instructions you give concerning your medical care should you become unable to speak for yourself.
One type of advance directive is known as a durable power of attorney (POA) for health care. In this case, you sign a legal document authorizing a person you respect and trust to make legally binding medical decisions for you if you’re unable to do so. A POA is often recommended because the appointed person can make decisions in situations not covered in a regular advance directive. Whatever you decide, put your wishes in writing. Laws regarding advance directives and POAs vary from state to state, but a written document is more likely to be respected.
Coming to terms with your illness
Having a serious illness may be the hardest thing you’ve ever dealt with. For some people, having a strong faith or a sense of something greater than themselves makes this process easier. Others seek counseling from someone who understands life-threatening illnesses, such as a medical social worker, psychologist or chaplain. Many people also take steps to ensure that their end-of-life wishes are known and respected.
In fact, the greatest fears of many people with a life-threatening illness include being subjected to treatments they don’t want, becoming a burden to their loved ones, and spending their last weeks or months in a hospital away from familiar surroundings. The welcome news is that many more choices now exist for people with a terminal illness.
Hospice care, for example, provides a special course of treatment to terminally ill people. This allows family and friends — with the aid of nurses, social workers and trained volunteers — to care for and comfort a loved one at home or in a hospice residence. It also provides emotional, social and spiritual support for people who are ill and those closest to them. Although most people under hospice care remain in their own homes, the program is available anywhere — including nursing homes and assisted living centers. For those who stay in a hospital, palliative care specialists can provide comfort, compassionate care and dignity.