The stomach is a hollow organ in the upper abdomen, under the ribs. It is part of the digestive system. Food moves from the mouth through the esophagus to the stomach. In the stomach, the food becomes liquid and muscles in the stomach wall push the liquid into the small intestine.
The wall of the stomach has five layers: the inner (mucosa), submucosa, muscle, subserosa, and outer layers.
Stomach cancer starts in cells, the building blocks that make up tissues. Tissues make up the stomach and other organs of the body. Stomach cancer is also called gastric cancer.
Stomach cancer begins when a normal cell becomes abnormal. Normal cells grow and divide to form new cells as the body needs them. When normal cells grow old or get damaged, they die, and new cells take their place. Sometimes, this process goes wrong. New cells form when the body doesn't need them, and old or damaged cells don't die as they should. The buildup of extra cells often forms a mass of tissue called a growth, polyp, or tumor.
Tumors in the stomach can be benign (not cancer) or malignant (cancer). Benign tumors are not as harmful as malignant tumors.
The source for this information is the National Cancer Institute.
Doctors can't always explain why one person gets stomach cancer and another doesn't. However, certain risk factors may make a person more likely than others to develop stomach cancer. A risk factor is something that may increase the chance of getting a disease.
Having risk factors does not mean a person will get stomach cancer. Many people who get stomach cancer have none of these risk factors, and many people who have known risk factors never have cancer. People with one or more of these risk factors should talk with the doctor about cancer risk.
Risk factors for stomach cancer include the following:
- Helicobacter pylori (H. pylori) infection: H. pylori is a bacterium that commonly infects the inner lining of the stomach. Infection with H. pylori can cause stomach inflammation and peptic ulcers. It also increases the risk of stomach cancer, but only a small number of infected people develop stomach cancer.
- Long-term inflammation of the stomach: People who have conditions associated with long-term stomach inflammation (such as the blood disease pernicious anemia) are at increased risk of stomach cancer. Also, people who have had part of their stomach removed may have long-term stomach inflammation and increased risk of stomach cancer many years after their surgery.
- Smoking: Smokers are more likely than nonsmokers to develop stomach cancer. Heavy smokers are most at risk.
- Family history: Close relatives (parents, brothers, sisters, or children) of a person with a history of stomach cancer are somewhat more likely to develop the disease themselves. If many close relatives have a history of stomach cancer, the risk is even greater. Learn more from our Family Cancer Assessment Clinic.
- Poor diet: Studies suggest that people who eat a diet high in foods that are smoked, salted, or pickled have an increased risk for stomach cancer. On the other hand, people who eat a diet high in fresh fruits and vegetables may have a lower risk of this disease.
- Lack of physical activity: A lack of physical activity may increase the risk of stomach cancer.
- Obesity: People who are obese may have an increased risk of cancer developing in the upper part of the stomach.
Early stomach cancer often does not cause symptoms. As the cancer grows, the most common symptoms include the following:
- Blood in the stool
- Difficulty swallowing
- Discomfort or pain in the stomach
- Feeling full or bloated after a small meal
- Nausea and vomiting
- Vomiting blood
- Weight loss
Most often, these symptoms are not due to cancer. People with these symptoms should tell their doctor so any health problems can be diagnosed and treated as early as possible.
Currently, there are no screening methods for stomach cancer.
If symptoms suggest stomach cancer, the doctor will try to find out what's causing the problems.
The doctor will ask the patient about his or her personal and family health history and may order blood or other tests to help make a diagnosis:
- Physical exam: The doctor feels the abdomen for fluid, swelling, or other changes. The doctor will also check for swollen lymph nodes.
- Endoscopy: The doctor uses a thin lighted tube (endoscope) to look into the stomach. The tube is passed through the mouth and esophagus to the stomach.
- Biopsy: The doctor uses an endoscope to remove tissue from the stomach and sends it to a lab. The doctor in the lab looks at the tissue under a microscope for signs of cancer. The removal of tissue to look for cancer cells is called a biopsy. In most cases, a biopsy is the only sure way to tell whether cancer is present.
If stomach cancer is diagnosed, the doctor needs to learn the extent (stage) of the disease to help choose the best treatment.
Staging is a careful attempt to find out the following:
- How deeply the cancer has invaded the wall of the stomach
- Whether the cancer has invaded nearby tissues
- Whether the cancer has spread, and if so, to what parts of the body
The doctor may order one or more of these staging tests:
- Chest x-ray: An x-ray of the chest can show whether cancer has spread to the lungs.
- CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of the inside of the body. The patient may receive contrast material by mouth or by injection into a blood vessel. The contrast material makes abnormal areas easier to see. Tumors in the liver, pancreas, or elsewhere in the body can show up on a CT scan.
- Endoscopic ultrasound: The doctor passes a thin lighted tube (endoscope) down the throat, which has been numbed with anesthetic. A probe at the end of the tube sends out sound waves that can't be heard. The waves bounce off tissues in the stomach and nearby organs. A computer creates a picture from the echoes. The picture can show how deeply the cancer has invaded the wall of the stomach. The doctor may use a needle to take tissue samples of lymph nodes.
- Laparoscopy: The surgeon inserts a thin lighted tube (laparoscope) into the abdomen. The surgeon may remove lymph nodes or take tissue samples for biopsy.
Stages of Stomach Cancer
Stage 0: The cancer cells are found only in the inner layer of the stomach. The doctor may call this carcinoma in situ.
Stage I: The cancer has grown deeper into the submucosa or the muscle layer of the stomach. There may also be cancer in the lymph nodes.
Stage II: The cancer has grown through the inner submucosa, muscle, or outer layer of the stomach. There may also be cancer in the lymph nodes.
Stage III: The cancer has grown through the muscle or outer layer of the stomach and has spread to the lymph nodes or nearby organs.
Stage IV: In stage IV stomach cancer, one of the following is found:
- Cancer cells have spread to more than 15 lymph nodes.
- The tumor has invaded nearby organs and at least one lymph node.
- Cancer cells have spread to distant organs.
At Huntsman Cancer Institute, stomach cancer is treated by a team of specialists, including gastroenterologists (doctors who specialize in treating problems of the digestive organs), surgeons, medical oncologists (doctors who treat cancer with medicine), radiation oncologists (doctors who treat cancer with radiation), nurses, dietitians, and social workers.
Common treatment options for stomach cancer include the following:
- Radiation therapy
- Clinical trials
A patient may have a combination of treatments. The treatment that's right for each patient depends on many factors:
- The size and location of the cancer in the stomach
- Whether the cancer has invaded nearby structures
- Whether the cancer has spread to lymph nodes or other parts of the body
- The patient's age and general health
The health care team can describe all of the treatment choices, the expected results of each, and the possible side effects. Because cancer therapy often damages healthy cells and tissues, side effects are common. Side effects may not be the same for each person, and they may even change from one treatment session to the next.
There are different types of surgery for stomach cancer. The type depends mainly on where the cancer is located. The surgeon may remove the whole stomach or only the part that has the cancer. The surgeon can talk about these types of surgery and which may be right for the patient.
- Partial (subtotal) gastrectomy for tumors at the lower part of the stomach: The surgeon removes the lower part of the stomach with the cancer. The surgeon attaches the remaining part of the stomach to the intestine. Nearby lymph nodes and other tissues may also be removed.
- Total gastrectomy for tumors at the upper part of the stomach: The surgeon removes the entire stomach, nearby lymph nodes, parts of the esophagus and small intestine, and other tissues near the tumor. Rarely, the spleen also may be removed. The surgeon then connects the esophagus directly to the small intestine.
Most people with stomach cancer get chemotherapy. Chemotherapy uses drugs to kill and control cancer cells. Learn more about this treatment in our introduction to chemotherapy video.
Radiation therapy uses high-energy rays to kill cancer cells. Radiation therapy only affects cells in the treated area. Radiation therapy is usually given with chemotherapy to treat stomach cancer.
The radiation comes from a large machine outside the body. The machine aims beams of radiation at your cancer. Patients go to a hospital or clinic for treatment. This type of treatment uses computers to closely target the cancer, which protects healthy tissue near the stomach.
These studies discover and evaluate new and improved cancer treatments. Patients are encouraged to talk with their doctors about participating in a clinical trial or any questions regarding research studies. For more information, also visit HCI's clinical trials website.
When you or someone you love is diagnosed with cancer, concerns about treatments and side effects, hospital stays, and medical bills are common. You may also worry about caring for your family, work, or normal daily life.
There are several places you can go for support:
- Your health care team can answer your questions and talk to you about your concerns. They can help you with any side effects and keep you informed of all your treatments, test results, and future doctor visits.
- Our Patient and Family Support Services offer emotional support and resources for coping with cancer and its impact on daily life to Huntsman Cancer Institute (HCI) patients and their families.
- The Linda B. and Robert B. Wiggins Wellness-Survivorship Center offers many programs to increase the quality of life and well-being of HCI patients and their families.
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Gastrointestinal Cancer Program
Did You Know?
- Each year in the United States, about 13,000 men and 8,000 women are diagnosed with stomach cancer. Most are over 70 years old.
- Studies suggest that people who eat a diet high in foods that are smoked, salted, or pickled have an increased risk for stomach cancer. On the other hand, people who eat a diet high in fresh fruits and vegetables may have a lower risk of this disease.
- Early stomach cancer often does not cause symptoms.