For the first time, researchers have found a direct interaction between cigarette smoke carcinogens and the human papillomavirus (HPV) that could lead to an increased risk of cervical cancer. Cervical cancer is the third most common cancer type in women worldwide, and over 90 percent of cases have been linked to HPV.

However, many women carry HPV, and it only progresses to cervical cancer in a small percentage of women. Cigarette smoking could be a reason for the progression.

Researchers found that after exposure to benzo[a]pyrene (BaP), a major carcinogen in cigarette smoke, levels of HPV type 31 increased 10-fold, and levels of HPV types 16 and 18 were also elevated. According to the researchers, “BaP modulation of the HPV life cycle could potentially enhance viral persistence, host tissue carcinogenesis, and permissiveness for cancer progression.”