Oral contraceptive use and gestational choriocarcinoma.

Substantial advances have occurred in the treatment of gestational trophoblastic disease, but little is known about the etiology. Routine screening of data from a case-control study of several diseases revealed an association between gestational choriocarcinoma and oral contraceptive (OC) use. A detailed analysis of 23 cases of gestational choriocarcinoma, 34 of invasive hydatidiform mole, and 49 of hydatidiform mole, each matched on age and geographic area to 4 controls who had been pregnant at least once, was carried out. Relative to women who had never used oral contraceptives, the estimated relative risk of choriocarcinoma for women who had used oral contraceptives for at least 5 years was 6.0 (95% CI, 1.3 to 28); for invasive mole and hydatidiform mole, the relative risks were elevated but not statistically significant. Oral contraceptive use has also been associated with an increased risk of gestational choriocarcinoma in a recent study conducted in the western U.S. These findings raise the hypothesis that long-term oral contraceptive use, or a correlate of use such as exposure to sexually transmitted infections, increases the risk of one or more of the manifestations of gestational trophoblastic disease.