Stomach cancer develops from abnormal cells in the lining of the stomach. The lining is made of glandular tissue that digests food and moves nutrients to the small intestine after you swallow your food. In stage 1 stomach cancer, the cancer cells haven’t spread from the lining to other parts of the body.
There are many different types of stomach cancer. The most common are squamous cell carcinoma and adenocarcinoma. But other types of cancer can also form in the stomach, such as lymphoma and sarcoma. Cancers that grow from lymphocytes or stromal cells are called sarcomas. Cancers that grow from other tissues, such as ovarian cancer or breast cancer, are called carcinomas.
Early symptoms of stomach cancer are similar to other illnesses, such as indigestion and stomach pain. The cancer may grow and cause trouble with your digestive system, such as blood in your stool or loss of appetite.
The first step in diagnosing stomach cancer is a physical exam. Your doctor will feel for a mass in your stomach and ask about your recent symptoms. They may order blood tests to look for anemia and check your stomach for signs of bleeding. If the tests show a possible problem, your doctor will do a biopsy or endoscopy to find out if you have cancer. A biopsy is a minor surgery to remove a tiny piece of tissue for testing under a microscope.
A biopsy or endoscopy is usually done in the hospital. Then, your doctor will use the results of the tests and a medical history to decide what treatment is best for you. Your doctor will consider how far the cancer has grown, what type it is and whether it has spread to other areas of your body.
Doctors use two systems to stage cancer: clinical staging and pathological staging. In clinical staging, doctors use your test and scan results to find out how far the tumor has grown. In stage 1, the tumor has grown into the inner layers of the stomach wall and touched one or two nearby lymph nodes. But it hasn’t spread to other areas of your body.
In stage 2, the tumor has spread to more deeply into the stomach wall. It might also be in the connective tissue outside the stomach or nearby lymph nodes. In stage 3, the tumor is in all the layers of the stomach and sometimes in other organs near it, such as the spleen and colon. Cancer might have also spread to other areas of your body, like the liver or lungs.
Doctors don’t know what causes most stomach cancers, but they do know some things that increase your risk. These include having a close relative who has had the disease, infection with the bacteria helicobacter pylori (H. pylori), and some inherited genetic conditions, such as Lynch syndrome. Working in certain industries, such as coal mining or metal fabrication, can also increase your risk.
