What is Stomach Cancer?
Stomach (gastric) cancer starts in the stomach, a sack-like organ that holds food and begins the digestion process. Cancer can start in any part of the stomach.
The stomach has five layers. As cancer grows deeper into the layers, the prognosis for the patient gets worse. Starting from the inside, the innermost layer is called the mucosa.
Next is a supporting layer called the submucosa which is surrounded by the muscularis, a layer of muscle that moves and mixes the stomach contents. The next two layers, the subserosa and the serosa (the outermost) layer, act as wrapping for the stomach. Stomach cancer usually starts in the mucosa (adenocarcinoma).
Facts: According to the Illinois State Cancer Registry, in 2008, about 990 new cases of stomach cancer will be diagnosed in Illinois. Of these, about 620 will be in men and about 370 will be in women. About 610 Illinoisans are expected to die of stomach cancer in 2008.
What are the Causes and Risk Factors of Stomach Cancer?
Scientists have found several risk factors that make a person more likely to develop stomach cancer. The major risk factors include:
Bacteria infection: Infection with bacteria ( Helicobacter pylori) may be a major cause of stomach cancer. Long-term infection with these bacteria can lead to inflammation and damage of the inner layer of the stomach. This bacterium is also linked to some types of lymphoma of the stomach, but most people with this bacterium never develop cancer.
Tobacco: Smoking almost doubles the risk of stomach cancer.
Diet: An increased risk of stomach cancer is linked to diets high in smoked foods, salted fish and meats and pickled vegetables. Eating whole grain products and fresh fruits and vegetables that contain vitamins A and C appears to lower the risk of stomach cancer.
Obesity: Being overweight (excess body fat) or obese (abnormally high, unhealthy amount of body fat) is a major risk factor of many cancers, including cancer of the stomach.
Stomach surgery: Stomach cancer is more likely to occur in people who have had part of their stomach removed.
Type A blood: For unknown reasons, people with type A blood have a higher risk for stomach cancer.
Stomach polyps: Polyps are small mushroom-like growths on the lining of the stomach. Most types of polyps do not increase the risk of stomach cancer. One type, adenomatous polyps, sometimes develops into stomach cancer.
Gender: Stomach cancer is more than twice as common in men.
Ethnicity: The rate of stomach cancer is higher in Hispanics and African Americans than in non-Hispanic whites. The highest rates are seen in Asian/Pacific Islanders.
Age: Stomach cancer is most often diagnosed after the age of 50.
Family history: People with several close relatives who have had stomach cancer are more likely to develop this disease. Scientists are trying to learn how and why certain changes take place in the lining of the stomach and what part Helicobacter pylori play in stomach cancer.
What are the Symptoms of Stomach Cancer?
Stomach cancer can be difficult to find early. Often there are no symptoms in the early stages and in many cases the cancer has spread before it is found. When symptoms do occur, they are often so vague that the person ignores them. The common symptoms include:
- unintended weight loss and lack of appetite
- pain in the area of the stomach (abdominal pain)
- vague discomfort in the abdomen, often above the navel
- a sense of fullness just below the chest bone after eating a small meal
- heartburn, indigestion, or ulcer-type symptoms
- vomiting, with or without blood
- swelling of the abdomen
Many of these symptoms can be caused by conditions other than cancer. It is important to report any of these symptoms to a doctor.
How to Prevent Stomach Cancer
Even though the exact cause of stomach cancer is unknown, it is still possible to prevent many cases. Finding it early may be the best way to improve the chance of successful treatment and to reduce the number of deaths caused by the disease.
- Increased use of refrigeration for food storage (rather than salting, pickling and smoking) and changes in diet have helped lower the rate of stomach cancer over the past 60 years.
- A diet high in fresh fruits and vegetables can lower stomach cancer risk. Red meats, especially those high in fat or processed, should be limited.
- Stop tobacco and alcohol usage.
- It is not yet clear whether people with chronic (on-going) infection with Helicobacter pylori bacteria should be treated to prevent stomach cancer. This issue is being researched.