Why Does the Global, Historic Impact of Stomach Cancer Matter?

Gastric (stomach) cancer was, until recently, the leading cause of cancer death worldwide, and has been a common cancer since at least the 1700s, as evidenced by early epidemiologic studies. So what causes stomach cancer? Who’s most likely to get it? And why has the incidence of stomach cancer dropped globally over the past century?

According to the American Cancer Society, 90 to 95 percent of people diagnosed with stomach cancer have an adenocarcinoma, a cancer that develops in the stomach’s interior wall (mucosa). The initial stages of this cancer can take years to develop and produce only mild symptoms. Stomach cancer often advances beyond the mucosa into one or more of the stomach wall’s four additional layers before it’s detected.

The National Cancer Institute (NCI) SEER Program notes that in the U.S., stomach cancer is more common in men than in women. Asian-Americans, Native Americans, and Hispanics are the three ethnic groups most likely to be diagnosed with stomach cancer, followed closely by African-Americans. Stomach cancer is an older person’s disease, being diagnosed most frequently between the ages of 65 and 74.

Helicobacter pylori (H. pylori) is a bacterium that can infect the mucus lining of the stomach. Spread through contaminated food and water (as well as mouth-to-mouth), it’s often acquired during childhood, with those living in areas lacking sanitation more likely to be infected. According to the NCI, H. pylori is a leading cause of stomach ulcers; and since the 1980s, H. pylori has been accepted as an important cause of stomach cancer.

In its earliest stages, stomach cancer is often treatable with surgery. If caught early enough, it’s usually possible to do a partial gastrectomy, which removes just part of the stomach. Because some of the stomach is retained, the patient is still able to eat fairly normally. A full gastrectomy, which removes the entire stomach, will require a change in eating habits, and/or feeding through an external tube. Radiation and chemotherapy are sometimes used in conjunction with this surgery.

According to SEER, an estimated 28,000 Americans will be diagnosed with stomach cancer in 2017; this represents 1.7 percent of all new cancer cases. Approximately 10,960 Americans will die of the disease this year. The five-year survival rate for stomach cancer is 30.6 percent. In contract, for prostate cancer, it’s 98.6 percent. Of the most common cancers, only lung cancer and pancreatic cancer are more deadly than stomach cancer.

The World Health Organization (WHO) estimates that about 952,000 people worldwide were diagnosed with stomach cancer in 2012, the latest year for which statistics exist. This makes stomach cancer the fifth most common cancer globally, trailing cancers including lung, colorectal, and prostate. Stomach cancer is the third leading cause of cancer death worldwide, with about 723,000 people dying of the disease in 2012.

References to stomach cancer are noted in ancient Egyptian hieroglyphics; a major statistical analysis of the disease was undertaken in 18th century Italy. Until the 1980s, when it was surpassed by lung cancer, stomach cancer was the leading cause of cancer death worldwide, including in the United States and Europe. However, the incidence of stomach cancer has dropped considerably over the past century, with the U.S. starting to show a decline as early as 90 years ago.

Thanks to the advent of refrigeration, many people eat fresh fruits and vegetables more often. The antioxidants in these foods help reduce a person’s overall cancer risk. In addition, refrigeration has encouraged people to reduce their consumption of salted, pickled, and smoked foods, all of which are a dietary risk factor for stomach cancer. America’s decline in stomach cancer, beginning in the 1930s, is directly linked to the increased availability of electricity and refrigeration.

According to the World Cancer Research Fund International, Asia, the Caribbean, and Latin America currently represent the areas of the world with the highest incidence of stomach cancer: specifically Korea, Mongolia, Japan, Guatemala, and China, the world’s top five. Populations in North America and Africa show the lowest incidence of stomach cancer. About 72 percent of stomach cancers occur in less developed countries.

While some stomach cancer risk factors — age, sex, ethnicity — can’t be changed, there are ways to potentially lower your risk of contracting the disease. According to the NCI, eating a diet high in fruits and vegetables (and low in salted, pickled, and smoked foods); and not smoking have been shown to decrease risk. If you’re prone to stomach ulcers or gastritis (stomach inflammation), get tested to see if H. pylori may be a factor; and if it is, ask your doctor about next steps.