[National Institutes of Health (NIH) News Bulletin, December 23, 2021] – Chronic infection with the bacterium Helicobacter pylori (H. pylori) is listed as known to be a human carcinogen. This is included in the 15th Report on Carcinogens, bringing the total list to 256 substances that are known, or reasonably anticipated, to cause cancer in humans.
H. pylori is a bacterium that colonizes in the stomach and can cause gastritis and peptic ulcers. Most people do not show symptoms. Chronic infection may lead to stomach cancer and a rare type of stomach lymphoma. Infection primarily occurs from person-to-person contact, especially in crowded housing conditions, and may occur by drinking well water contaminated with H. pylori.
People living in poverty and certain racial, ethnic, and immigrant groups are disproportionately affected by H. pylori infection. Treatment of infected people who have stomach ulcers or signs of stomach infection can decrease their risk of cancer.
Cancer affects almost everyone’s life, either directly or indirectly. As the identification of carcinogens is a key step in cancer prevention, publication of the report represents an important government activity towards improving public health
Rick Woychik, Ph.D., director of the National Institute of Environmental Health Sciences and NTP
The Report on Carcinogens identifies many different environmental factors, collectively called substances, including chemicals; infectious agents, such as viruses; physical agents, such as X-rays and ultraviolet radiation; and exposure scenarios. A substance is listed as either known to be a human carcinogen or reasonably anticipated to be a human carcinogen, to indicate the potential hazard.
The report does not include estimates of cancer risk because many factors affect whether a person will or will not develop cancer. Those include the carcinogenic potency of the substance, the level and duration of exposure, and an individual’s susceptibility to the carcinogenic action of the substance.
Source:
National Institutes of Health (NIH) News Bulletin, December 23, 2021