Yet Another Deadly Link

Studies have long linked smoking and cancer of the cervix, which is expected to kill at least 6,000 women in the U.S. this year. Now a new study has not only confirmed the link but also concluded that women who breathe smoke from others' cigarettes -- so-called passive smoke -- are equally at risk for cervical cancer.

The report, the first thorough evaluation of the effects of smoking on women with cervical cancer, was published last week in the Journal of the American Medical Association by a team of researchers at the University of Utah Medical School. It found that women who smoke are about three times as likely to develop cancer of the cervix as nonsmokers. But the study, which also sought to assess the damage done by exposure to passive smoke, produced a surprise: women who inhaled passive smoke for three or more hours a day were not only more likely to have cervical cancer than those who did not but were as much at risk as active smokers.

In addition, the researchers found that passive smoke in the home was a greater risk than such smoke in other locations, possibly because it was more constantly present. They also discovered that smoking and being constantly exposed to the smoke of others put women at even greater risk than either factor separately.

Doctors have long known about other risk factors for cervical cancer, including sexual activity at an early age and sex with multiple partners. And they have implicated some types of human papillomavirus (HPV), which causes genital warts, as the probable culprit. The University of Utah researchers, however, could only speculate about a possible mechanism by which smoking may cause cervical cancer. Harmful components of cigarette smoke, they suggest, may travel through the blood into the tissues of the cervix and somehow activate the virus.

Others viewed the findings with caution, noting that a cause-and-effect relationship between passive smoking and cervical cancer remains to be shown. Still, declared Lawrence Garfinkel, an epidemiologist at the American Cancer Society, "cervical cancer should probably be added to the list of tobacco- induced cancers."