X-rays, Gamma Rays Added to Carcinogen List

There also is some evidence to suggest that chronic hepatitis C infection may increase the risk of B-cell lymphoma.

The human papillomaviruses (HPVs) that were listed as carcinogens are of the genital-mucosal type. Epidemiologic studies have shown that that these types cause cervical cancer. Case-control studies have reported strong associations of HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 58, and 59 with cervical cancer.

In particular, cohort studies have shown that infection with HPV-16 or with high-risk HPVs as a class occurs before the development of high-grade cervical intraepithelial neoplasia, which is thought to be a precursor of invasive cancer.

HPV-16 has also been associated with other anogenital cancers, especially cancer of the vulva.