What is stomach cancer (gastric cancer)?
With stomach cancer — also called gastric cancer — cancer cells grow out of control in your stomach. Cancer can form anywhere in your stomach. In the U.S., most cases of stomach cancer involve abnormal cell growth in the place where your stomach meets your esophagus (gastroesophageal junction). In other countries, where gastric cancer is more common, cancer usually forms in the main part of your stomach.
About 95% of the time, stomach cancer starts in your stomach lining and progresses slowly. Untreated, it can form a mass (tumor) and grow deeper into your stomach walls. The tumor may spread to nearby organs like your liver and pancreas.
Who does stomach cancer affect?
Anyone can develop stomach cancer, but certain demographic factors may increase your risk. You’re more likely to get stomach cancer if:
- You’re 65 or over.
- You were assigned male at birth.
- Your ethnic background is East Asian, South or Central American or Eastern European.
How common is stomach cancer?
Stomach cancer is one of the most common cancers worldwide but is seen less often in the U.S. Only about 1.5% of stomach cancers get diagnosed each year in the U.S., where cases have been declining steadily for the past 10 years.
Symptoms and Causes
What are the signs and symptoms of stomach cancer?
Stomach cancer doesn’t typically cause symptoms during the early stages. Even the most common early signs of stomach cancer — often unexplained weight loss and stomach pain — don’t usually show up until the cancer is more advanced.
Symptoms of stomach cancer include:
- Loss of appetite.
- Trouble swallowing.
- Fatigue or weakness.
- Nausea and vomiting.
- Unexplained weight loss.
- Heartburn and indigestion.
- Black stool (poop) or vomiting blood.
- Feeling bloated or gassy after eating.
- Stomach pain, often above your belly button.
- Feeling full even after eating a small meal or snack.
Many of these symptoms are common in other conditions, too. See your provider to check if your symptoms are a sign of stomach cancer or another disease.
Can you feel a tumor in your stomach?
Your provider may be able to feel a mass in your stomach during a physical exam depending on how advanced the cancer is. More often, however, symptoms involve recognizing sensations in your stomach. Your stomach may frequently feel swollen, full or painful. The pain may start as mild and then get more intense as the disease progresses.
What causes stomach cancer?
Stomach cancer forms when there’s a genetic mutation (change) in the DNA of your stomach cells. DNA is the code that tells cells when to grow and when to die. Because of the mutation, the cells grow rapidly and eventually form a tumor instead of dying. The cancer cells overtake healthy cells and may spread to other parts of your body (metastasize).
Researchers don’t know what causes the mutation. Still, certain factors seem to increase the likelihood of developing stomach cancer. They include:
- Family history of stomach cancer.
- Helicobacter pylori (H. pylori) infection.
- Gastroesophageal reflux disease (GERD).
- Epstein-Barr virus infection.
- History of stomach ulcers or stomach polyps.
- A diet high in fatty, salty, smoked or pickled foods.
- A diet that doesn’t include many fruits and vegetables.
- Frequent exposure to substances like coal, metal and rubber.
- Smoking, vaping or chewing tobacco.
- Drinking too much alcohol.
- Autoimmune atrophic gastritis.
Several genetic conditions are associated with increased gastric cancer risk, including:
- Lynch syndrome.
- Peutz-Jeghers syndrome.
- Li-Fraumeni syndrome.
- Familial adenomatous polyposis.
- Hereditary diffuse gastric cancer.
- Common variable immunodeficiency (CVID).
Stomach cancer is more common in people with Type A blood, although researchers aren’t sure why.
Diagnosis and Tests
How is stomach cancer diagnosed?
Your provider will review your medical history, ask about your symptoms and perform a physical exam that may involve feeling for a mass in your stomach. They may order several tests to diagnose and stage stomach cancer.
Staging allows your provider to assess how much the cancer has spread. With stomach cancer, staging ranges from 0 (zero) to IV (four). Stage 0 means the cancer hasn’t spread beyond your stomach lining. Stage IV means that it’s spread to other organs.
- Upper endoscopy is commonly used to diagnose stomach cancer. During the procedure, your provider inserts a thin tube with a tiny camera at its tip (endoscope) into your mouth until it reaches your stomach. Small surgical instruments can pass through the endoscope, allowing your provider to remove a tissue sample (biopsy). The sample can be tested in a lab for cancer cells.
- Endoscopic ultrasound is a special kind of endoscopy that can help stage the cancer. The endoscope used has an ultrasound probe attached at its tip, that can take pictures of your stomach. It can show if the cancer’s spread from your stomach lining to your stomach wall.
- Radiologic tests, including a CT scan, barium swallow and MRI, can help identify tumors and other abnormalities that may be cancer-related. During a barium swallow, you drink a substance that makes your stomach lining more visible on an X-ray. A PET scan can show if cancer has spread throughout your body.
- Blood tests can offer information about how your organs are functioning. Poor organ function may indicate that cancer has spread to that organ.
- Laparoscopy is a type of surgery that allows your provider to assess cancer spread when less invasive methods, like imaging, haven’t provided enough information. During laparoscopy, your provider inserts a tiny camera into small cuts in your abdomen so they can see your organs directly.
Providers don’t screen for stomach cancer in the U.S. because it’s so rare. Still, if you have a condition that increases your risk, your provider may recommend regular procedures like an upper endoscopy to detect cancerous changes. Ask your provider about their recommendations based on your risk.
Management and Treatment
How is stomach cancer treated?
Treatment depends on how far your cancer’s spread, your health and treatment preferences. It often involves a care team that includes your primary care provider, a cancer specialist (oncologist) and a gastrointestinal specialist (gastroenterologist). They can advise you on treatment options.
Depending on how much the cancer’s spread, your provider may recommend surgery to remove precancerous cells, a tumor, or all or part of your stomach.
- Upper endoscopy: In the early stages, when the cancer is limited to your stomach's superficial (uppermost) layers, the cancer can be removed through an upper endoscopy. In this procedure (endoscopic submucosal dissection or endoscopic mucosal resection), a gastroenterologist cuts the tumor from your stomach wall and removes it through your mouth.
- Gastrectomy. Once the tumor spreads beyond your stomach's superficial layers, you'll need surgery to remove all or part of your stomach. Subtotal gastrectomy removes the part of your stomach affected by the cancer. Total gastrectomy removes your entire stomach. Your provider will connect your esophagus to your small intestine so that you can still eat following total gastrectomy.
Additional treatments attack cancer cells directly.
- Chemotherapy (chemo) uses drugs to shrink cancer cells, making them easier to remove before surgery. Chemotherapy can also kill the remaining cancer cells after surgery. It’s usually used in combination with radiation. Chemo may be used with targeted drug therapy, too.
- Radiation uses targeted energy beams like X-rays to destroy cancer cells. Radiation alone isn’t effective in treating stomach cancer, but it may be used alongside chemo before and after surgery. Radiation can also help relieve symptoms.
- Targeted drug therapy zeroes in on weaknesses in cancer cells, causing them to die. It’s often used with chemo in cancer that recurs (comes back) or that’s advanced.
- Immunotherapy helps your immune system identify and destroy cancer cells that may be hard to detect. It’s most commonly used in recurring or advanced cancer.
- Palliative care helps improve your quality of life as someone with a cancer diagnosis. Palliative care is specialized medical care that may include doctors, nurses and other specialists who can help with symptom relief. They can also provide additional support that complements the care you receive from your regular providers. You can receive palliative care alongside other treatments.
How can I prevent stomach cancer?
You can’t prevent stomach cancer, but you can reduce your risk if you:
- Treat H. pylori infection if you test positive. H. pylori infection is a significant risk factor for developing stomach cancer.
- Treat ulcers, gastritis and other stomach conditions promptly. Untreated stomach conditions, especially those caused by H. pylori bacteria, increase your risk of stomach cancer.
- Eat healthy. Eating a healthy diet that’s high in fruits and vegetables and low in salts and red meats can reduce your stomach cancer risk. Foods high in vitamin C, beta-carotene and carotenoids, such as citrus fruits, leafy green vegetables and carrots, are good sources of key nutrients.
- Avoid smoking and using tobacco products. Tobacco use increases your risk of stomach cancer and many other cancers.
- Maintain a healthy weight. What counts as a healthy weight varies from person to person. Ask your provider what a healthy weight means for you.
Outlook / Prognosis
Is stomach cancer curable?
Stomach cancer can be cured if it’s in the early stages. Often, though, diagnosis happens in later stages once symptoms begin. Ask your provider about the factors that play a role in your treatment outcomes.
What is the prognosis (outlook) for people who have stomach cancer?
The outlook for stomach cancer depends on the stage of cancer. People in the early stages of stomach cancer have a much better prognosis than those at a later stage. The 5-year survival rate for stomach cancer may be as high as 70% (for little spread) or as low as 6% (for advanced spread).
Speak with your provider for a more accurate assessment of your prognosis. The type of cancer you have, its spread, your health and how your cancer responds to treatment all shape your prognosis.
When should I see my healthcare provider?
If you’re at increased risk of stomach cancer, speak with your provider about the pros and cons of regular screenings. Otherwise, keep tabs on your symptoms. Many of the symptoms associated with stomach cancer may be signs of another condition. Only your provider can make a definitive diagnosis.
See your provider if you have symptoms like stomach pain and unexplained weight loss with or without symptoms, like:
- Trouble eating.
- Bloody or black stool.
What questions should I ask my doctor?
- Where is the cancer located?
- What stage of cancer do I have? What does this mean for my prognosis?
- What treatments are available to me?
- What are the benefits of this treatment? Potential risks?
- What other treatment options are available?
- How will my cancer diagnosis and treatment impact my everyday life?
- Should I get a second opinion?
A note from Cleveland Clinic
Stomach cancer isn’t always preventable, but it may be treatable if caught early. Depending on your cancer diagnosis, your provider may recommend surgery to remove cancer cells or tumors. They may suggest a combination of treatments that can kill or shrink the cancer cells. Ultimately, your prognosis depends on multiple factors you can discuss with your provider. Don’t hesitate to ask about treatment options, including their benefits and risks. Seek your providers’ guidance on what your cancer diagnosis means for you.
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