Infectious agents linked to 2.3 million cancer cases in 2024

A global scientific review published in The Lancet estimates that approximately 2.3 million new cancer cases in 2024 were attributable to viral or bacterial infections. This figure represents about 12% of all newly diagnosed cancers worldwide, meaning nearly one in eight cases is linked to infectious agents.

Researchers from the International Agency for Research on Cancer (IARC) identified 12 infectious agents classified as Group 1 carcinogens. The primary contributors are the bacterium Helicobacter pylori, which is linked to gastric cancer, and the Human Papillomavirus (HPV), which is responsible for the majority of cervical cancers. Together, these two infections account for more than 1.5 million estimated cases.

Other significant contributors include Hepatitis B (HBV) and Hepatitis C (HCV) viruses, which can cause liver damage, the Epstein-Barr virus (EBV), and several others such as HIV and various parasites. The study highlights that these cancers are potentially preventable through targeted infection control and vaccination efforts.