Molecular Epidemiology of Cutaneous Malignant Melanoma

Study Summary

This case-control study was planned to investigate the link of solar radiation with gene damage, host factors, and DNA repair proficiency in cutaneous malignant melanoma (CMM) risk. The hypothesis was that impaired DNA repair proficiency is associated with an increased risk of CMM due to unrepaired DNA damage, particularly in subjects with dysplastic nevi, poor tanning ability or genetic susceptibility. The study was reviewed as an RO1 Grant from the National Cancer Institute in 1995. Subject enrollment, which included clinical evaluation, epidemiologic questionnaires, and skin and blood sample collection, was completed in 1999 on approximately 180 melanoma cases and 180 controls identified in Italy. The study protocol and consent form both included the measurement of genetic and biochemical factors and DNA repair capacity. DNA repair proficiency was measured in lymphocytes by the host cell reactivation assay, and sun exposure was evaluated by means of a detailed questionaire. Photographs of the back of the subjects were taken to allow nevi count. Minimal erythemal dosage was measured in all subjects to estimate skin sun sensitivity 24 hours after skin's UV-irradiation. Skin color was ascertained on the inner side of the forearm by means of a Minolta chromometer. The aim of this protocol is to continue analysis of the biological samples already collected, as originally outlined in the study protocol. In particular, we plan to measure polymorphisms in genes that may lead to susceptibility to melanoma. Initially we will concentrate on variation in genes involved in repairing damaged DNA, but plan to look at a broad group of candidate susceptibility genes.