Stomach cancer, or gastric cancer, is a rare but potentially dangerous form of cancer. Because stomach cancer symptoms can be mistaken for less serious problems such as indigestion or heartburn, stomach cancer is often not found until its advanced stages.
What is stomach cancer?
Many times, people refer to the entire region between the hips and chest as the stomach. In medical terms, however, the word ‘stomach’ refers only to the muscular, sac-like organ that sits in the upper abdomen.
After you chew and swallow food, it moves through a hollow tube called the esophagus into the stomach. There, the stomach mixes this food with gastric juices to begin the digestion process.
Stomach cancer occurs when the cells in the stomach's lining divide uncontrollably, forming a tumor. As cancer progresses, the tumor may invade and destroy surrounding tissue, block the passage of food, or break off and spread (metastasize) to other organs.
Around the world, the majority of stomach cancer cases affect the main portion of the stomach, called the body. Stomach cancer can also affect the distal stomach, close to where the stomach meets the small intestine. In the United States, stomach cancer usually affects the gastroesophageal junction (also known as the cardia), where the stomach meets the esophagus. While the rates of stomach cancer, in general, are declining, cancers in the gastroesophageal junction are increasing.
Stomach cancer types
There are different types of stomach cancer, depending on the cells in which cancer starts. These include:
Adenocarcinomas: Adenocarcinoma refers to cancer that starts in gland cells. The cancer begins in the stomach’s mucosal —or inner— layer and grows outward, invading the other layers of the stomach wall. This is the most common type of stomach cancer, accounting for 90% of all stomach cancer cases.
Gastrointestinal stromal tumors (GIST): Cancer that affects a type of cells (Interstitial cells of Cajal) in the gastrointestinal tract, most often the stomach or small intestine. They are also called gastric sarcomas.
Carcinoid tumors: Carcinoid tumors affect the hormone-producing cells of the stomach. They are also called neuroendocrine tumors.
Stomach cancer statistics
According to the National Cancer Institute, an estimated 27,600 new cases of stomach cancer will be diagnosed in the United States in 2020. More than 60% of these diagnoses will be for people age 65 or older. The five-year survival rate for the disease is 32%. Because stomach cancer symptoms can be mistaken for less serious problems such as indigestion or heartburn, stomach cancer is often not found until its advanced stages. This can lead to worse outcomes.
Stomach cancer risk factors
Although the exact cause of stomach cancer is not known, certain factors seem to increase your risk of developing the disease. These include:
Gender: The majority of stomach cancer patients are male.
Age: Most individuals who develop stomach cancer are older than 55, although stomach cancer can be diagnosed in younger individuals. According to the National Cancer Institute, the median age at diagnosis is 68 years old.
Ethnicity: In the United States, stomach cancer occurs more often in Hispanic Americans, African Americans, and Asian/Pacific Islanders than in non-Hispanic whites.
Geography: Stomach cancer is more prevalent in Japan, China, Southern and Eastern Europe, and Central and South America than in Northern and Western Africa, South Central Asia, and North America. This may be due to differences in diet, the rate of infection with Helicobacter pylori (a type of bacteria), and the environment.
Infection with Helicobacter pylori (H. pylori): This type of bacteria is a common cause of stomach ulcers and may cause chronic inflammation in the stomach lining. This sometimes leads to pre-cancerous changes in cells, increasing the risk of stomach cancer.
Exposure to chemicals: People who work around certain chemicals have a higher risk for stomach cancer. These include:
- Those working in the rubber, metal, coal and timber industries
- Those who have been exposed to asbestos fibers
Obesity: People who are obese have a higher risk of cancer in the part of the stomach nearest the esophagus.
Tobacco and alcohol abuse: Smoking and drinking excessive amounts of alcohol appear to increase the likelihood of cancer in the upper part of the stomach. Some studies have shown that smoking doubles the risk of stomach cancer.
Food preservation and improper food storage and preparation: Eating foods preserved through pickling, salting and drying or that contain nitrates can be a risk factor. Eating foods that have not been stored or prepared correctly is also a risk factor.
Medical conditions: Having any of the following may increase your risk for stomach cancer:
- Pernicious anemia
- Chronic stomach inflammation (gastritis) and intestinal polyps
- Acid reflux or chronic indigestion
- Menetrier disease
- Epstein-Barr virus infection
- History of stomach lymphoma, a type of cancer that affects the lymph nodes, which are small, bean-shaped organs that help transport immune cells and remove waste from tissue
- Type A blood
- Prior stomach surgery
Family history: In rare cases, stomach cancer can be passed down from one generation to the next. Additionally, if close relatives have had stomach cancer or have hereditary cancer syndromes such as Hereditary Diffuse Gastric Cancer syndrome (caused by CDH1 mutation), hereditary non-polyposis colon cancer (HNPCC) or Li-Fraumeni syndrome, you may be at a higher risk of stomach cancer. Genetic testing may be used to identify genetic predisposition for stomach cancer.
Not everyone with risk factors gets stomach cancer. However, if you have risk factors, you should discuss them with your doctor.
Why choose MD Anderson for stomach cancer care?
When you receive treatment for stomach cancer at MD Anderson's Gastrointestinal Center, you are the focus of some of the world's leading experts. Your personal team of experts may include oncologists, surgeons and radiation oncologists, as well as specially trained nutritionists, nurses and others. Together, they create a care plan using treatments designed to provide optimum results with the least impact on your body.
World-class care
Stomach cancer surgery is often challenging, and your highest chances for a successful outcome are with a surgeon who has a high degree of experience and skill in these highly-specialized procedures. Because MD Anderson is one of the nation's most active cancer centers, our surgeons use the latest techniques to perform a large number of delicate stomach cancer surgeries each year, with outcomes higher than many other cancer centers.
Trailblazing treatment
With groundbreaking research, MD Anderson's physicians have pioneered many improvements in treating stomach cancer. We have led some of the largest international studies on chemotherapy for stomach cancer, and we continue to explore advanced techniques including:
- Robotic surgery
- Intraperitoneal chemotherapy (IP)
- Hyperthermic Intraperitoneal Chemotherapy (HIPEC)
- Intensity-modulated radiation therapy (IMRT)
- Stereotactic body radiation therapy (SBRT)
- Immunotherapy/Targeted therapy
- Genomic/Molecular Profiling
Continual support
At MD Anderson you're surrounded by the strength of one of the nation's largest and most experienced comprehensive cancer centers, which has all the support and wellness services needed to treat the whole person – not just the disease. Stomach cancer can have a marked impact on your life, and our experts guide you every step of the way to help you cope and adjust.
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