The role of oral contraceptives (OC) in the aetiology of cutaneous malignant melanoma (CMM) has been controversially discussed over the last two decades. In an extensive literature search we identified 18 case-control studies, published between 1977 and 1996, offering information on this relationship. Using a meta-analytical approach we combined the study-specific risk estimates and derived a summary odds ratio of 0.95 (95% confidence interval: 0.87-1.04). Based on the data of 3796 cases and 9442 controls, we thus found no evidence for an aetiological role of OC use in the development of CMM.
PIP: The possible association between cutaneous malignant melanoma (CMM) and oral contraceptive (OC) use was explored through a review of the 18 case-control studies on this relationship published during 1977-96. These studies encompassed 3796 cases and 9442 controls. Although the odds ratios (ORs) ranged widely, from 0.13 to 1.85, most studies (14 of 18) produced similar ORs within the interval 0.82-1.15. The summary OR for the total sample was 0.95 (95% confidence interval: 0.87-1.04). Thus, the meta-analysis pointed to an absence of any effect of OCs on the risk of CMM. Separate analyses based on design factors such as type of exposure ascertainment (personal, telephone interview, postal interview, or register information) or the origin of control groups (population or hospital) failed to change this trend. Only 2 prospective cohort studies on this association were located. The estimated risk ratios in these studies, 0.92 and 0.85, each accompanied by wide confidence intervals due to small numbers of cases (58 and 32, respectively), provided additional support for the conclusion that OC use has no detectable effect on CMM risk.