Cancer Hazard Evaluations for Contemporary Needs: Highlights From New National Toxicology Program Evaluations and Methodological Advancements

Abstract

Abstract The National Toxicology Program strives to raise awareness of cancer hazards in our environment. Identifying cancer hazards is key to primary prevention, informing public health decision making, and decreasing the global cancer burden. In December 2021, the US congressionally mandated 15th Report on Carcinogens was released, adding 8 new substances to the cumulative report. Chronic infection with Helicobacter pylori is listed as “known to be a human carcinogen.” Antimony trioxide and 6 haloacetic acids found as water disinfection by-products—dichloroacetic acid, dibromoacetic acid, bromochloroacetic acid, tribromoacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid—are listed as “reasonably anticipated to be a human carcinogen.” A new dashboard provides interactive visualization and interrogation of the 256 listed substances, their uses, and associated cancers. Also, the National Toxicology Program recently published a Cancer Hazard Assessment Report on exposure scenarios associated with circadian disruption, concluding that persistent night shift work can cause breast cancer and certain lighting conditions may cause cancer. As highlighted in these reports and evaluations, we are evolving our approaches to meet contemporary challenges. These approaches include focusing on real-world exposures and advancing our methods to address challenges in cancer hazard assessments (eg, developing more structured approaches to evaluate mechanistic data and incorporating read-across approaches to assess chemicals lacking adequate human or animal cancer data). To promote public health, we provide information on environmental health disparities and disease prevention. Building on these efforts, we aim to continue our contributions to the war on cancer, declared 50 years ago.