Stomach Cancer: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Stomach Cancer?
A gastroenterologist, a doctor who treats digestive problems, often does the first tests. After a diagnosis, you are referred to a gastrointestinal oncologist, a doctor who treats cancers of the stomach and intestines. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is stomach cancer?
Stomach cancer, also called gastric cancer, is cancer of the stomach. The stomach is an organ between the esophagus (the food pipe) and the small intestine. It mixes food with stomach acid and helps digest protein.
It is hard to find stomach cancer in its early stages. Because it is often found late, it can be hard to treat.
Symptoms
Indigestion and stomach discomfort can be early symptoms. Other problems can cause the same symptoms, so they do not always mean cancer.
In advanced cases, a person may have:
- Blood in the stool.
- Vomiting.
- Weight loss that has no clear cause.
- Jaundice, which is yellow skin and eyes.
- Trouble swallowing.
Causes and who gets it
Stomach cancer mostly affects older people. About two-thirds of people who have it are over age 65. Your risk is higher if you:
- Have had a Helicobacter pylori (H. pylori) infection, which is a stomach infection caused by bacteria.
- Have had stomach inflammation, which is swelling and irritation of the stomach lining.
- Are a man.
- Eat lots of salted, smoked, or pickled foods.
- Smoke cigarettes.
- Have a family history of stomach cancer.
How doctors diagnose it
A doctor may ask about your history and feel your belly. Blood tests can check for anemia, a low red blood cell count, which can be a sign of bleeding in the stomach. A stool test can look for hidden blood.
An upper endoscopy looks inside the esophagus, stomach, and the first part of the small intestine with a thin, lighted tube. The doctor can take a small sample of tissue, called a biopsy. A pathologist, a doctor who studies tissue, checks it under a microscope for cancer. A barium swallow is a series of x-rays taken after you drink a liquid that coats the stomach. A CT scan makes detailed pictures of the inside of the body.
Biomarker testing looks for genes, proteins, and other substances in the cancer cells. Some biomarkers affect how certain cancer treatments work. Your doctor will then recommend tests to find out if the cancer has spread, and if so, how far. This is called staging.
Treatment
Treatment can include surgery, chemotherapy, radiation, or a combination. Your plan may include more than one type of treatment. Doctors consider the stage of the cancer, your overall health, and your preferences.
Surgery is a common treatment. Gastrectomy, which is removal of part or all of the stomach, is the main surgery for stomach cancer. A subtotal gastrectomy removes the part of the stomach that contains cancer and nearby lymph nodes. A total gastrectomy removes the entire stomach. For early-stage cancer, an endoscope can sometimes remove it from the lining of the digestive tract.
Chemotherapy uses drugs to stop cancer cells from growing. It may be given before surgery to shrink the tumor. After surgery, some patients are given chemotherapy, radiation therapy, or both to kill any cancer cells that are left. Radiation therapy uses high-energy x-rays to kill cancer cells. Targeted therapy and immunotherapy drugs are also used for stomach cancer.
If a tumor blocks the way into or out of the stomach, a stent may be placed. A stent is a thin, expandable tube that helps food pass.
When to see a doctor
Talk to a doctor if you have blood in your stool, vomiting, weight loss you cannot explain, jaundice, or trouble swallowing. These can be signs of advanced stomach cancer.
Call 911 or go to the emergency room if you vomit blood, have severe belly pain, or faint.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either type of doctor can review your symptoms, order first tests, and refer you to a gastroenterologist. During and after cancer care, they can help keep your overall health and medicines organized.
Common questions
Does stomach cancer cause symptoms early on?
It can. Indigestion and stomach discomfort can be early symptoms, but other problems can cause the same symptoms, and stomach cancer is hard to diagnose in its early stages.
What raises the risk of stomach cancer?
Several things raise the risk, including a past H. pylori infection, stomach inflammation, smoking, and a family history of stomach cancer. Eating lots of salted, smoked, or pickled foods also raises the risk.
How is stomach cancer treated?
Stomach cancer is treated with surgery, chemotherapy, radiation, or a combination. The plan depends on the stage of the cancer, your overall health, and your preferences.
Why is stomach cancer hard to treat?
Stomach cancer can be hard to treat because it is often found late. It is hard to diagnose in its early stages.
Sources
- MedlinePlus - Stomach Cancer
- National Cancer Institute - Stomach Cancer Treatment
- National Cancer Institute - Stomach Cancer Diagnosis and Tests
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
