A review of 23 studies concludes that women who smoke are at 60-percent higher risk of developing cervical cancer than nonsmokers, with risk rising with the number of cigarettes smoked, Reuters reported April 7.

Women who start smoking at a young age also are at higher risk, although duration of smoking did not appear to increase exposure, according to researchers taking part in the International Collaboration of Epidemiological Studies of Cervical Cancer. "It is not clear why this association was present," said lead researcher Amy Berrington de Gonzales. "One possible explanation is that duration of smoking was reported less accurately than age at starting smoking, and age at starting smoking is acting as a surrogate for duration of smoking, i.e. earlier age at starting smoking is a marker of longer duration."

The study was published in the March 15, 2006 issue of the International Journal of Cancer.