| Melanoma is a serious form of skin cancer that arises in melanocytes---cells that produce skin pigment called melanin. Although melanoma accounts for only about 4% of all skin cancer cases, it causes most skin cancer-related deaths. It is one of the most common cancers in the United States. To date, few studies have examined exposures such as natural and artificial ultraviolet (UV) radiation or the protective effects of skin self-examination while controlling for a comprehensive vector of candidate confounders including atypical nevi. The objective of this research, using a standard case-control approach, was to further elucidate the etiology of melanoma as well as the potential protective effect of skin screening. Risk factors evaluated for melanoma included timing, dose, and frequency of modifiable exposures: solar UV radiation (Study 1), artificial UV radiation (Study 2), and the efficacy of skin examination (Study 3). The case-control analyses included descriptive, stratified, and multivariate analysis. The results of Study 1 emphasize that age-dependent patterns of exposure confer risk; which underlines the important and independent role played by intermittent sun exposure during childhood and adulthood. The results of Study 2 support an age- and device-dependent association between artificial tanning device use and melanoma that is complicated by the wide variety of emission spectra that characterize the lamps, era and patterns of device use, and lag time between device exposure and melanoma diagnosis. The results of Study 3 showed no associations between incidence of melanoma and conducting skin self-examination (SSE), frequency of SSE, or SSE that included examination of the back using a mirror. These findings do not support previous evidence that SSE for melanoma reduces the overall incidence of melanoma, but demonstrates that the protective effects of skin cancer screening are most strongly realized in high-risk individuals. This research is germane to future melanoma research and to public health efforts to reduce melanoma risk. |
