Stomach cancer grows in the cells that line the stomach. It accounts for an estimated 1.5% of all new cancers diagnosed in the United States every year, and it is more common in men than in women. This cancer is also more common in aging adults, as six in every 10 people who are diagnosed with stomach cancer are 65 or older.
Causes of Stomach Cancer
Stomach cancer occurs when DNA in cells in the stomach starts to change, or mutate. This can cause those cells to grow rapidly and out of control, and eventually form growths called tumors. Over time, cancerous cells can destroy nearby tissues and spread to other parts of the body—including to other organs.
Certain lifestyle factors can increase your risk for stomach cancer. It’s possible to prevent this cancer by eating healthy foods and avoiding harmful behaviors like smoking.
Risk factors for stomach cancer include:
- Smoking
- Eating lots of salty foods
- Eating lots of smoked foods
- Low vegetable and fruit intake
- Obesity
- Gastroesophageal reflux disease (GERD—a condition in which stomach contents flow back up into the esophagus)
- Gastritis, or stomach inflammation
- Stomach infection caused by Helicobacter pylori
- Family history of stomach cancer
Symptoms of Stomach Cancer
Indigestion and pain in the upper belly are early symptoms of stomach cancer. However, many people with this cancer do not experience symptoms until the disease is advanced.
Common signs and symptoms of stomach cancer may include:
- Frequent heartburn
- Loss of appetite
- Unintentional weight loss
- Abdominal pain and discomfort
- Nausea and vomiting
- Feeling full after eating small portions
- Frequent belching
- Difficulty swallowing
- Fatigue
- Black or dark stool
- Constant bloating after eating
- Jaundice (yellowing of the skin and the whites of the eyes)
Diagnosing Stomach Cancer
Many symptoms of stomach cancer are the same as those of other health conditions. If you think you may have stomach cancer, your healthcare provider will perform one or more tests to arrive at a proper diagnosis.
Stomach cancer can usually be diagnosed using an upper endoscopy and biopsy. During an upper endoscopy, your doctor will insert a thin tube with a tiny camera on the end (called an endoscope) down your esophagus and into the stomach. This allows your doctor to view the inside of your stomach to look for signs of stomach cancer including polyps and tumors. At the same time, your doctor may also use the endoscope to perform a biopsy, which involves removing a small piece of stomach tissue that can be tested for stomach cancer.
If you are diagnosed with stomach cancer, your provider may perform additional testing to determine the stage of your disease. Blood testing, ultrasound, and CT scan are common tests that can show the stage and progression of stomach cancer. In the event imaging tests are unable to provide clear images of the inside of your stomach, your provider may recommend surgery.
Treatments for Stomach Cancer
Stomach cancer is often treated using many of the same treatments that are used to treat other cancers, including surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapy. The goal of treatment is to remove or destroy all cancer cells.
Surgery
During surgery for stomach cancer, doctors cut small tumors and cancers out of stomach tissue or remove part or all of the stomach affected by cancer. The surgical removal of the stomach is known as gastrectomy. After removing your stomach, your surgeon will connect the esophagus to the small intestine to allow food to move freely through your digestive system.
Chemotherapy
Chemotherapy utilizes one or more medications to shrink or destroy cancer. It may be performed before surgery to shrink tumors and make them easier to remove, or after surgery to kill any remaining cancer cells. Your provider can talk to you in more detail about the risks and side effects associated with chemotherapy for stomach cancer, which include diarrhea, hair loss, and nerve damage.
Radiation Therapy
Radiation therapy uses high-powered beams of energy—such as that emitted by X-rays—to destroy cancer cells. It may be combined with chemotherapy to shrink cancerous growths. Common side effects associated with radiation therapy for stomach cancer include nausea, vomiting, and fatigue.
Immunotherapy
Immunotherapy for stomach cancer employs medications that help stimulate the immune system so it can fight cancer more effectively. Nivolumab and pembrolizumab are immunotherapy drugs approved to treat advanced-stage stomach cancer. Both medications work by targeting and blocking a protein called PD-1 on immune system cells to shrink and slow the growth of stomach tumors.
Targeted Therapy
Targeted therapy for stomach cancer uses drugs that specifically target certain components of cells and pathways that play a role in this type of cancer. For instance, stomach cancer cells tend to contain high amounts of a protein called HER2. Therefore, drugs that target this protein can be useful in destroying the cancer.
Targeted therapy drugs that may be used to treat stomach cancer include:
- Trastuzumab
- Fam-trastuzumab deruxtecan
- Ramucirumab
- Larotrectinib
- Entrectinib
Preventing Stomach Cancer
Practicing certain healthy behaviors can help you reduce your risk for stomach cancer even if this disease runs in your family. Your doctor can talk to you in more detail about your risk after reviewing your personal and family medical histories.
Steps you can take to prevent stomach cancer include:
- Eating healthy foods such as fruits, vegetables, nuts, fish, and poultry
- Limiting your intake of foods high in salt
- Not smoking
- Reducing your alcohol intake
- Exercising regularly
- Losing excess weight
- Working with your doctor to manage GERD and gastritis
Contact your doctor right away if you are experiencing symptoms of stomach cancer, as early treatment is key to improving your survival rate and well-being. Your doctor can discuss your treatment options and work with you to improve your condition.