Stomach cancer
From MayoClinic.com Special to CNN.com

Introduction

 

Although the incidence of stomach cancer has declined dramatically in the United States and Western Europe in the last 50 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 the type of diet.

Stomach cancer is more readily treated when caught early. Unfortunately, by the time it causes symptoms, the disease is often at an advanced stage and may have spread beyond the stomach. Yet there is encouraging news. You can reduce your risk of this serious cancer by making a few changes in your lifestyle.

 

Signs and symptoms

 

The earliest sign of both noncancerous (benign) and cancerous (malignant) stomach tumors 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).

When the cancer is more advanced, you may experience signs and symptoms such as:

Having one or more of these signs and symptoms doesn't necessarily mean you have stomach cancer. Other 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. If you're an average adult, it's about the size of a small melon, but can stretch at the sides to hold nearly 1 gallon of food and liquid. Your stomach folds in on itself when it's empty and expands when you eat or drink.

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. Under normal conditions, your stomach produces 2 to 3 quarts of gastric juices every day. One of these, hydrochloric acid, is so corrosive it can dissolve iron nails. Your stomach's delicate tissues are protected from this powerful acid by a thick, jelly-like mucus that coats the stomach lining.

Once the food in your stomach is thoroughly broken down and mixed, muscular contractions push it toward the pyloric valve, which leads into the upper portion of your small intestine (duodenum). The valve opens just enough to release a scant eighth of an ounce of food at a time. It may take three to four hours for your stomach to empty after you eat, depending on your diet. Foods high in fat increase the amount of time it takes for your stomach to empty.

 

 

Types of stomach cancer
The great majority of stomach cancers are adenocarcinomas, which start in the glandular cells in the mucosa, the stomach's innermost lining. Adenocarcinomas are sometimes divided into types 1 and 2:

Although adenocarcinomas account for about 95 percent of all stomach cancers, other forms of the disease can sometimes occur, including:

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:

 

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. Having both H. pylori and a form of a gene that causes low stomach acid greatly increases your risk of stomach cancer.

Other risk factors for stomach cancer include:

 

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.

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 indicative of stomach cancer, these signs may result from other conditions that require medical care.

 

Screening and diagnosis

 

To help diagnose stomach cancer and rule out other possibilities, your doctor may recommend one or more of the following diagnostic tests:

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:

 

Treatment

 

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.

Treatment options include the following:

Drug therapy
In 2002, the Food and Drug Administration approved the anti-leukemia drug (Gleevec) to treat some gastrointestinal stromal tumors. Gleevec, which is taken in capsule form once a day, belongs to a new class of medications that specifically target 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.

Gleevec is approved only for GISTs 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, Gleevec 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:

 

Self-care

 

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:

 

Coping skills

 

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:

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.

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 oral 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.

 

July 21, 2006