Cancer of the stomach, or gastric cancer, is the fifth most common cancer worldwide in women and the fourth most common in men, says Dr. Amit Bhatt, a gastroenterologist at Cleveland Clinic. “Although, in general, the rates of gastric cancer are going down, it remains one of the most common [causes of] cancer death in the world,” he says.

Risk Factors

Gastric cancer doesn’t affect all populations equally. Fortunately for people living in the U.S., the rates of gastric cancer in North America are among the lowest in the world. However, gastric cancer is a major cause of death in Asian countries, Europe, Central America and South America. In fact, in Japan, where gastric cancer is very common, doctors recommend yearly screening via endoscopy beginning at age 40, says Dr. Aravind Sanjeevaiah, an assistant professor at UT Southwestern who specializes in gastrointestinal cancers. (As an interesting comparison, Bhatt says the rates of esophageal cancer, another digestive tract cancer, are low in Japan and high in the U.S.)

The other major risk factor for gastric cancer is the H. pylori bacteria, a common cause of peptic ulcers, according to the Mayo Clinic. Bhatt says individuals with H. pylori infections are three times as likely to develop gastric cancer. These infections often don’t cause symptoms (although frequent heartburn may indicate an infection and should prompt a visit to your doctor). Eradicating H. pylori infections with antibiotics seems to reduce the risk for gastric cancer.

[Read: Stomach Cancer — Awareness and Advances Needed.]

Improved sanitation in industrialized nations may explain the overall decreasing rates of gastric cancer, Sanjeevaiah says. Better sanitation means fewer people become infected with H. pylori. He says the introduction of the refrigerator is also one of the main reasons gastric cancer incidence has declined because people started consuming more fresh fruits and vegetables and less smoked meat and canned vegetables.

Age, pernicious anemia (vitamin B deficiency), certain genetic syndromes like familial adenomatous polyposis (an inherited disorder in which people develop polyps at a young age, and if the colon is not removed, the growths will become cancerous), smoking and alcohol are also risk factors for gastric cancer. When you combine any of these risk factors with an H. pylori infection, it multiplies your risk for gastric cancer, Bhatt says.

As with other cancers, catching gastric cancer early improves prognosis. Because the incidence of gastric cancer in the U.S. is low, doctors don’t routinely screen people at average risk. If you have a hereditary condition that raises your risk for gastrointestinal cancers, however, your doctor may recommend screening.

Symptoms and Diagnosis

About 90 percent of gastric cancers are gastric adenocarcinomas, which begin in the innermost layer of the wall of the stomach. Bhatt says because of the expandable nature of the stomach, tumors can grow quite large before they cause noticeable symptoms, which is why these cancers are often not diagnosed until they reach an advanced stage. The five-year survival rate for gastric cancer, even with treatment, is only about 20 percent, Bhatt says. “It is a very lethal cancer, ” he adds.

[See: 10 Seemingly Innocent Symptoms You Shouldn’t Ignore.]

Symptoms of gastric cancer can include weight loss, abdominal discomfort (including bloating and nausea), loss of appetite and black or bloody stools if the tumor bleeds.

Doctors diagnose gastric cancer primarily through endoscopy. During an endoscopic procedure, your doctor passes a thin, lighted scope through your mouth or nose into your stomach. With the scope, your doctor can see inside your stomach and take a biopsy (small tissue sample) if needed. If your doctor finds an abnormality, an endoscopy with ultrasound will allow him or her to see how much the tumor has invaded the stomach wall, Bhatt says. CT and PET scans can help diagnose gastric cancer that has spread (metastasized).

Treating Gastric Cancer

Treatment for gastric cancer depends on the stage of the cancer at diagnosis. “In early stages, surgery alone might be sufficient, especially if the cancer does not involve lymph nodes and the small intestine,” Sanjeevaiah says. “If it’s bigger than a few centimeters, the patient may need more than surgery.”

Bhatt says early tumors that haven’t invaded the stomach wall may be removed with endoscopic microsurgery. This preserves the stomach and is associated with high cure rates. The downside, he says, is that the procedure leaves the organ (the stomach) at risk of tumors in the body. Patients with gastric cancer are closely monitored for recurrences.

[See: 7 Innovations in Cancer Therapy.]

For cases where the gastric tumor is more advanced, patients may need surgery to remove all or part their stomach along with chemotherapy before surgery or chemotherapy and radiation after surgery to prevent recurrence. The rate of recurrence in gastric cancer is high, Sanjeevaiah says. The type of surgery depends on where the tumor is. If it’s in the upper portion of the stomach, if it’s widespread or if you have a genetic disease associated with gastrointestinal cancers, your surgeon may remove your entire stomach, a procedure called gastrectomy.

After a gastrectomy, your surgeon will reconstruct a small pouch using tissue from the small intestine The stomach’s primary role is to hold food and to break down large pieces of food until it passes into the small intestine, where most of our digestion occurs.

The best way to prevent gastric cancers is to not smoke, eradicate H. pylori infections and avoid smoked and pickled foods and salted meats and fish.

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What You Should Know About Stomach Cancer originally appeared on usnews.com