Stomach Cancer

Stomach cancer, also called gastric cancer, is a malignant tumor arising from the lining of the stomach. There has been a significant decrease in the number of people diagnosed with stomach cancer in the past 60 years. According to the American Cancer Society, the estimated numbers of new cases (people diagnosed with the condition) and deaths from gastric cancer in the United States in 2012 will be:

New cases: 21,320
Deaths: 15,070
Stomach cancers are classified according to the type of tissue where they originate. The most common type of stomach cancer is adenocarcinoma, which starts in the glandular tissue of the stomach and accounts for 90% to 95% of all stomach cancers. Other forms of stomach cancer include lymphomas, which involve the lymphatic system and sarcomas, which involve the connective tissue (such as muscle, fat, or blood vessels).

There are many known risk factors for stomach cancer, but it is not known exactly how these factors cause cells of the stomach lining to become cancerous. This is the subject of ongoing research.
Several changes thought to be pre-cancerous can occur in the stomach lining.

In chronic atrophic gastritis, the normal glands of the stomach are either decreased or absent. There is also some degree of inflammation (the stomach cells are damaged by cells of the immune system). Atrophic gastritis is often caused by H pylori infection. It can also be caused by an autoimmune reaction, in which a person’s immune system attacks the cells lining the stomach. Some people with this condition go on to develop pernicious anemia or other stomach problems, including cancer. It is not known exactly how this condition might progress to cancer.

Another possible pre-cancerous change is intestinal metaplasia. In this condition, the normal lining of the stomach is replaced with cells that closely resemble the cells that usually line the intestine. People with this condition usually have chronic atrophic gastritis as well. How and why this change occurs and progresses to stomach cancer is not well understood. This might also be related to H pylori infection.

Recent research has provided clues on how some stomach cancers form. For instance, H pylori bacteria, particularly certain subtypes, can convert substances in some foods into chemicals that cause mutations (changes) in the DNA of the cells in the stomach lining. This may also explain why certain foods such as preserved meats increase a person’s risk for stomach cancer. On the other hand, some of the foods that might lower stomach cancer risk, such as fruits and vegetables, contain antioxidants that can block substances that damage a cell’s DNA.

During the past few years, scientists have made a lot of progress in understanding how certain changes in DNA can cause normal stomach cells to grow abnormally and form cancers. DNA is the chemical in each cell that carries our genes — the instructions for how our cells function. We look like our parents because they are the source of our DNA. But DNA affects more than how we look..
The exact cause of stomach cancer is unknown, but a number of factors can increase the risk of the disease, including:

Gender -- men have more than double the risk of getting stomach cancer than women.
Race -- being African-American or Asian may increase your risk.
Genetics -- genetic abnormalities and some inherited cancer syndromes may increase your risk
Geography -- stomach cancer is more common in Japan, the former Soviet Union, and parts of Central America and South America.
Blood type -- individuals with blood group A may be at increased risk.
Advanced age -- stomach cancer occurs more often around ages 70 and 74 in men and women, respectively.

Family history of gastric cancer can double or triple the risk of stomach cancer.
Lifestyle factors such as smoking, drinking alcohol, and eating a diet low in fruits and vegetables or high in salted, smoked, or nitrate-preserved foods may increase your risk
Helicobacter pylori (H. pylori) infection of the stomach. H. pylori is a bacterium that infects the lining of the stomach and causes chronic inflammation and ulcers.
Certain health conditions including chronic gastritis, pernicious anemia, gastric polyps, intestinal metaplasia, and prior stomach surgery.

Work-related exposure due to coal mining, nickel refining, and rubber and timber processing and asbestos exposure.

 In more advanced cancer, you may have:
Discomfort in the upper or middle part of the abdomen.
Blood in the stool (which appears as black, tarry stools).
Vomiting or vomiting blood.
Weight loss.
Pain or bloating in the stomach after eating.
Weakness or fatigue associated with mild anemia (a deficiency in red blood cells).
Some treatments:
Chemotherapy
Chemotherapy is the use of drugs to destroy cancer cells, usually by stopping the cancer cells’ ability to grow and divide. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication.

Systemic chemotherapy is delivered through the bloodstream to reach cancer cells throughout the body. Common ways to give chemotherapy include an intravenous (IV) tube placed into a vein using a needle or in a pill or capsule that is swallowed (orally). A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a set period of time. A patient may receive one drug at a time or combinations of different drugs at the same time.
The side effects of chemotherapy depend on the individual and the dose used, but they can include fatigue, risk of infection, nausea and vomiting, hair loss, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished.

Targeted therapy
Targeted therapy is a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. This type of treatment blocks the growth and spread of cancer cells while limiting damage to healthy cells.
Recent studies show that not all tumors have the same targets. To find the most effective treatment, your doctor may run tests to identify the genes, proteins, and other factors in your tumor. As a result, doctors can better match each patient with the most effective treatment whenever possible. In addition, many research studies are taking place now to find out more about specific molecular targets and new treatments directed at them. Learn more about targeted treatments.
A patient with later-stage cancer whose stomach tumor has too much of the protein HER2, called HER2-positive cancer, may benefit from receiving trastuzumab (Herceptin) with chemotherapy.
Talk with your doctor about possible side effects for a specific medication and how they can be managed.

Getting care for symptoms and side effects
Cancer and its treatment often cause side effects. In addition to treatment to slow, stop, or eliminate the cancer, an important part of cancer care is relieving a person’s symptoms and side effects. This approach is called palliative or supportive care, and it includes supporting the patient with his or her physical, emotional, and social needs.

Palliative care can help a person at any stage of illness. People often receive treatment for the cancer and treatment to ease side effects at the same time. In fact, patients who receive both often have less severe symptoms, better quality of life, and report they are more satisfied with treatment.

Palliative treatments vary widely and often include medication, nutritional changes, relaxation techniques, and other therapies. You may also receive palliative treatments similar to those meant to eliminate the cancer, such as chemotherapy, surgery, and radiation therapy. Talk with your doctor about the goals of each treatment in your treatment plan.

Before treatment begins, talk with your health care team about the possible side effects of your specific treatment plan and supportive care options. And during and after treatment, be sure to tell your doctor or another health care team member if you are experiencing a problem so it is addressed as quickly as possible. Learn more about palliative care.

Metastatic stomach cancer
If cancer has spread to another location in the body, it is called metastatic cancer (stage IV in the Stages section).

Patients with this diagnosis are encouraged to talk with doctors who are experienced in treating this stage of cancer, because there can be different opinions about the best treatment plan. Learn more about seeking a second opinion before starting treatment, so you are comfortable with the treatment plan chosen. This discussion may include clinical trials.