Uveal melanoma, hormonal and reproductive factors in women.

In a case-control study, we explored a potential association between uveal melanoma and reproductive factors in women. Responses from telephone interviews of 186 women diagnosed with uveal melanoma were compared with responses of 423 women without this disease. All women resided in 11 U.S. western states. We observed a decreased risk of uveal melanoma for women who had ever been pregnant [relative risk (RR) = 0.60, 95% confidence interval (CI) = 0.37 -0.95], with an increase in this protective effect with more live births after adjustment for age, menopausal status, eye color, and skin sensitivity to the sun (1-2 births, RR = 0.47,95% CI 0.29-0.78; 3-4 births, RR = 0.38, 95% CI = 0.22-0.64; 5 or more births, RR = 0.33, 95% CI = 0.15-0.71). The largest effect was observed between nulliparous and parous women. No other reproductive factors, including use of oral contraceptives or postmenopausal estrogens, were shown to be related to risk for uveal melanoma. We conclude that most reproductive factors in this population play little or no role in the etiology of uveal melanoma. The association with number of live births must be confirmed in other studies to assure that it is unrelated to confounding factors not measured in this study.