Cigarette smoking has emerged as a powerful influence in the development of cervical cancer and of distorted cells that are precursors of malignancy, researchers say.
These distorted cells, which can be detected in Pap tests, frequently evolve into a serious cancer if left untreated.
In a new study at the Montefiore Medical Center in New York, of 60 women who had advanced cervical cancer, 85 percent were smokers. There also was evidence to suggest that the remainder had significant exposure to passive smoking, generally through spouses who smoked. Studies in the last five years had pointed to a connection, but none had shown such a strong effect.
"Cervical cancer and abnormal Pap tests are clearly related to smoking, and that deserves major headlines," Dr. Carolyn D. Runowicz, who wrote the study, said yesterday in a telephone interview.
Dr. Runowicz, director of the Division of Gynecologic Oncology at Montefiore, presented the study at a meeting last month of the European Society of Therapeutic and Radiation Oncology.
Risks that have been previously identified include having intercourse at an early age, multiple sexual partners and infection with the human papilloma virus, a sexually transmitted disease that usually produces no symptoms. The only group of women who do not seem to get cervical cancer is nuns.
"In old movies you see Lauren Bacall drawing on a cigarette in bed after sex, looking glamorous and sophisticated," Dr. Runowicz said. "That's the image I'm fighting. If you're going to have sexual intercourse, not only should you use condoms but also you shouldn't light up."
There are 13,500 cases of cervical cancer and 6,000 deaths from the disease every year, according to the American Cancer Society. Each year 1.2 million women have abnormal Pap tests, which show the distorted cells, or dysplasia.
"They might not if they didn't smoke," Dr. Runowicz said.
Scientists are not sure how smoking increases a woman's risk. Some experts theorize that nicotine may have a predilection for the type of cells, squamous, that cover both the lungs and the cervix.
Others feel that smoking may be a mild suppressant of immune function, allowing human papilloma virus infections to fester. Such infections are known to promote abnormal Pap tests.
Experts emphasize that cervical cancer is theoretically preventable, since it usually develops slowly over years from areas of dysplasia. The presence of dysplasia is identified through a routine Pap test, and the precancerous regions can be destroyed in a doctor's office by laser surgery or by freezing the area.
Occasionally, more extensive surgery is advised. Marilyn Quayle, for instance, had a hysterectomy in July for severe precancerous abnormalities of the cervix.
Although abnormal Pap smears and cervical cancer affect all age groups, they are far more common among poor women, who often cannot afford screening and who are more likely to smoke.
Dr. Runowicz said that while the smoking rate among men had declined significantly in the last decade, the percentage of women who smoke has declined only slightly. Cigarettes have already been implicated in lung cancer as well as head, neck and bladder cancer.