Stomach Cancer Overview

Stomach cancer is one in a group of cancers called gastrointestinal (GI) cancers. They can occur in the GI tract or other organs that make up your digestive system. Stomach cancer, also called gastric cancer, is a disease in which cancer (malignant) cells form in the stomach lining. 

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Types of Stomach Cancer

The stomach has five layers, and most stomach cancers (90-95%) begin in the mucosa, the deepest layer. This is called adenocarcinoma of the stomach. 

Other rare types of stomach cancers include: 

  • Carcinoid tumors start in hormone-producing cells of the stomach but rarely spread to other organs. 
  • Gastrointestinal stromal tumors (GIST) are rare tumors that start in special cells in the wall of the GI tract (digestive tract). Not all GISTs are cancerous. GISTs can be found anywhere in the digestive tract, but most are found in the stomach. 
  • Lymphoma is a cancer of immune system tissue, sometimes found in the stomach wall. 

What Causes Stomach Cancer?

Doctors don't know exactly what causes cancer cells to start growing in the stomach. Stomach cancer is more likely to happen if you have a high risk for the disease. 

Factors that make you more vulnerable to developing stomach cancer include:

  • Infection with a common bacterium called Helicobacter pylori (H. pylori); can also cause stomach inflammation and ulcers
  • Inflammation in your gut called gastritis
  • Having pernicious anemia or growths in your stomach called polyps
  • Being over age 50
  • Being male
  • Smoking
  • Being overweight
  • Eating a diet high in smoked, pickled, salty foods or highly processed foods
  • Having had stomach surgery for an ulcer 
  • Having Blood Type A
  • Having had an Epstein-Barr virus infection
  • Working in coal, metal, timber, or rubber industries
  • Exposure to asbestos
  • Being a minority – Asians, Pacific Islanders, Hispanics, and African-Americans are more likely to get stomach cancer than Whites
  • Having a close family member with stomach cancer 

Preventing Stomach Cancer

Preventing stomach cancer is the best option for your health. Work with your doctor to treat stomach infections or ulcers from H. pylori. Eat healthily and include fresh fruits and vegetables every day. Avoid salty, pickled, cured, highly processed, and smoked foods. Get to and maintain a healthy weight. Don't smoke because it doubles your risk of stomach cancer. If you regularly take aspirin or NSAIDs (Aleve or Advil), talk to your doctor about how these drugs affect your stomach.

Symptoms of Stomach Cancer

Symptoms of stomach cancer can vary from person-to-person; however, here are some of the more common symptoms: 

  • Frequent indigestion or heartburn
  • Poor appetite
  • Weight loss (without trying)
  • Stomach pain 
  • Cramps
  • Discomfort in the belly, usually above the navel
  • Feeling full after eating a small amount
  • Heartburn or indigestion
  • Bloating
  • Blood in your stool
  • Diarrhea
  • Nausea
  • Vomiting
  • Fatigue

Patients with more advanced stomach cancer may have a weakness, trouble swallowing, eyes or skin become yellowish, or stomach swelling. 

Getting a Diagnosis 

There are several ways your doctor or oncologist (a doctor specializing in cancer diagnosis and treatment) determines if you have stomach cancer. Your doctor will start with a physical exam and take your medical history to check for stomach cancer risk factors. The doctor may order some tests, including:

  • Blood tests
  • Upper endoscopy, which puts a thin, flexible tube with a small camera down your throat to look into your stomach
  • Upper GI series requires you to drink a chalky liquid that contains barium to coat your stomach and make it show up clearly on an X-ray
  • CT (computed tomography) scan, a very powerful X-ray, shows a detailed cross-section of tissue and can detect tumors
  • Biopsy means a small amount of tissue is removed and studied under a microscope to detect cancer cells, often done during an endoscopy  

Stages of Stomach Cancer

After you receive a stomach cancer diagnosis, your doctor will determine if cancer has spread, and if so, how far. This process is called staging, and it also helps your doctor determine your best treatment options.

The American Joint Committee on Cancer's (AJCC) TNM system is the staging system most often used for stomach cancer. TNM refers to:

  • T: Tumor size and extent of tumors
  • N: Lymph node involvement (small organs that are part of your body's germ-fighting system)
  • M: Metastasis, whether or not cancer has spread to other areas 

Cancer can be stage 0, I, II, III, or IV. Generally, the higher the number, the larger the cancer tumor and its spread into nearby tissues.

  • Stage 0 means unhealthy cells are present but have not spread to nearby tissue. To prevent cancer, your oncologist will remove the cells with surgery. 
  • Stage I means you have a tumor in the stomach lining that may have spread to nearby lymph nodes. You'll probably undergo surgery and may also get chemotherapy (drugs that kill cancer) or radiation (destroys cancer cells with beams of high energy)
  • Stage II means cancer cells have spread into deeper layers of the stomach and lymph nodes. Surgery to remove part or all of your stomach, as well as nearby lymph nodes, is the main treatment at Stage II. Chemo and radiation will also be used before and/or after surgery.
  • Stage III cancer has spread to all layers of the stomach and nearby organs. Again, surgery, chemo, and radiation are the standard treatments.
  • Stage IV cancer has spread to many organs like your liver, lungs, or brain. This stage is the most life-threatening. Stomach removal surgery and chemo and radiation can sometimes cure it. If it does not, these treatments can help with symptoms.

Unfortunately, stomach cancer is often in an advanced stage before it is diagnosed because it is slow-growing cancer. Of all stomach cancer cases, about 42% of patients will live for at least one year after diagnosis; 19% will live for at least five years, and 15% will live at least ten years after diagnosis.

Treatment Options for Stomach Cancer

The earlier stomach cancer is discovered, the more treatment options and chances for recovery you will have. Stomach cancer treatments may include:

  • Surgery to remove cancer and part or all of the stomach and nearby lymph nodes.  
  • Chemotherapy (chemo) may be given before surgery to shrink the tumor and/or after surgery to remove any remaining cancer.  
  • Radiation therapy may be used with chemo before surgery to shrink the tumor and/or after surgery to kill the remaining cancer. Radiation is also used to slow the growth and ease the symptoms of advanced stomach cancer. 
  • Targeted therapy drugs may help when standard chemo drugs fail.   
  • Immunotherapy medicines can boost the patient's immune system, empowering it to find and destroy stomach cancer cells.

Who's on My Treatment Team? 

Before treatment begins, a team of doctors will create an individual treatment plan specifically targeted to your needs. Your treatment team will include a surgeon, medical oncologist, and radiation oncologist. A gastroenterologist and registered dietitian may also be included.

Nutrition is very important for patients undergoing stomach cancer treatment and recovery. Cancer can make it harder to eat and digest your food. Some patients may receive intravenous (IV) nutrition until they can eat on their own. A registered dietitian and Willamette Valley Cancer Institute's (WVCI) oncology nutritional services can help patients, and their caregivers understand how to get enough nutrition to stay strong during treatment and recovery. 

Through our affiliation with U.S. Oncology, WVCI's national research partner, clinical research trials are available to patients. Clinical trials often help find better therapies for treating cancer or new medications. 

Spotting stomach cancer early is key to successful treatment and healthy life. If you're having symptoms regularly, contact your doctor right away. If you have questions about your treatment, don't hesitate to call WVCI to speak with a doctor or counselor. WVCI is here to help you every step of your path back to good health. 

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