Having children, social characteristics, smoking and the risk of uveal melanoma: a case-control study.

Purpose: We analyzed data from the Risk Factors for Uveal Melanoma (RIFA) study to evaluate possible associations between uveal melanoma risk and having children, socioeconomic level and smoking. Methods: The RIFA study was a German case-control study conducted from September 2002 to March 2005. The study population consisted of 455 incident uveal melanoma patients (20-74 years of age) and 827 matched (age, sex, region of residence) population controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. Results: Women with children showed an increased OR (1.59, 95% CI 0.95-2.66) for uveal melanoma development compared to women without children. We estimated decreased ORs for subjects with higher socioeconomic level compared to the lowest status (upper secondary school leaving certificate: OR 0.68, 95% CI 0.49-0.94; higher education: OR 0.60, 95% CI 0.38-0.96). Ever smokers showed an OR of 1.19 (95% CI 0.92-1.55) compared to never smokers. Conclusion: The observed association between lower socioeconomic level and increased odds for uveal melanoma possibly represents a higher occupational uveal melanoma risk for occupational categories that are usually associated with lower socioeconomic status. Concerning having children and uveal melanoma development, we hypothesize that the observed association is mediated through alpha-melanocyte-stimulating hormone, a hormone that increases during pregnancy and is linked to pigmentation alterations in pregnant women.