Last December 21, 2021, the U.S. Department of Health and Human Services (HHS) released the 15th Report on Carcinogens. This is a science-based, congressionally mandated public health document that the National Toxicology Program (NTP) prepares for HHS. This cumulative report now includes 256 listings of substances of all types, such as chemical, physical, and biological agents, mixtures, and exposure circumstances, that are known or reasonably anticipated to cause cancer in humans. The report does not include cancer risk estimates because the factors that influence whether or not a person will develop cancer are multiple and combine throughout an individual's lifetime. These include the carcinogenic potency of the substances to which the individual is exposed, the level of carcinogenicity of the substances, the duration of exposure, and the individual's susceptibility to the carcinogenic action of the various substances.

In this 15th Report, HHS has listed chronic infection with Helicobacter pylori bacteria as a human carcinogen.. "Cancer affects nearly everyone's life, either directly or indirectly," said Rick Woychik, Ph.D., director of the National Institute of Environmental Health Sciences and NTP. "Because the identification of carcinogens is a key step in cancer prevention, the release of the report represents an important government activity to improve public health."

H. pylori is a bacterium that colonizes the stomach and can cause gastritis and peptic ulcers. Most people have no symptoms. Chronic infection can lead to stomach cancer and a rare type of stomach lymphoma, gastric MALT lymphoma. Infection occurs mainly through person-to-person contact, especially in unsanitary housing conditions, or by handling land irrigated with sewage or drinking contaminated water. Certain racial and ethnic groups are disproportionately affected by H. pylori infection, although it is not known whether there is a greater predisposition to infection or whether it is purely a matter of hygiene. Treatment of infected persons who have stomach ulcers or signs of stomach infection may reduce the risk of cancer.

Worldwide, H. pylori infection contributes to 780,000 new cases of cancer each year, approximately 6.2% of all cancer cases. Both stomach cancer and H. pylori infection disproportionately affect people living in poverty and certain racial, ethnic and immigrant groups. To address this public health problem, the Carcinogens Report details activities to prevent H. pylori-induced stomach cancer and recommendations from national and international working groups. Many expert groups recommend prevention and follow-up programs for individuals or populations at high risk for stomach cancer.

 

Source: National Toxicology Program; https://ntp.niehs.nih.gov/whatwestudy/assessments/cancer/roc/index.html