To the Editor.
—Irwin et al1 recently reported that women who used oral contraceptives had no increased risk of invasive cervical cancer compared with women who had never used oral contraceptives in a case-control study in Costa Rica. We recently concluded a case-control investigation of invasive cervical cancer in Maryland,2 which demonstrates that oral contraceptive use is protective against invasive disease (relative risk, 0.48; 95% confidence interval, 0.22 to 0.95). We conclude that rather than there being a biologically plausible association between oral contraceptives and invasive cervical cancer, the protective effect reflects increased screening among those seeking contraceptives, as others have suggested.3,4 Further, our data demonstrate that lifetime use of any type of contraceptive leads to protection from invasive disease (relative risk, 0.38; 95% confidence interval, 0.20 to 0.72), with diaphragm use (relative risk, 0.29; 95% confidence interval, 0.12 to 0.67) and vaginal spermicides (relative risk, 0.28;
Celentano DD. Oral Contraceptives and Cervical Cancer. JAMA. 1988;259(18):2696. doi:10.1001/jama.1988.03720180024021