Smoking raises virus-related cervical cancer risk

Cigarette smoking significantly increases the risk of cervical cancer associated with human papillomavirus (HPV) type 16, according to a report in the journal Cancer Epidemiology, Biomarkers & Prevention.

Numerous reports have linked HPV, and particularly type 16, with cervical cancer and recently a vaccine against this and other HPV types was approved for preventing the disease.

"Smoking has previously been implicated in cervical cancer, but our results suggest it is much higher in HPV-positive women (particularly those with high amounts of HPV) than HPV-negative women," Anthony S. Gunnell from the Karolinska Institute, Stockholm, told Reuters Health.

Gunnell and colleagues investigated the potential interaction between smoking and HPV-16 in the development of cervical cancer using a database of all Swedish women who participated in screening in Uppsala county between 1969 and 1995.

Current smokers had increased cervical cancer risk of nearly twofold, while the presence of HPV-16 increased the risk by eightfold, the report indicates.

Women who smoked for at least 5 years and harbored HPV-16 had the highest risk of cancer, and were 32-times more likely to develop the disease than nonsmokers without HPV-16.

"Our study revealed evidence suggestive of synergism between cigarette smoking (particularly duration of smoking) and HPV-16 in (cervical cancer) development, which occurs many years before diagnosis," the authors conclude.

"Of course, it is difficult to take full advantage of this knowledge (with respect to Pap screening practice) since HPV testing is not commonplace," Gunnell noted, "but women should perhaps be made aware of how much of an increased risk they may be in if they continue to smoke or start."

SOURCE: Cancer Epidemiology, Biomarkers & Prevention, November 2006.