Solar elastosis in cutaneous melanoma.

By studying more than 1,200 patients with cutaneous melanoma and long-term follow-up, I examined the relationship between solar elastosis and age at diagnosis of melanoma, key features of melanoma, and the outcome of overall survival in melanoma. I found that melanomas with elastosis were diagnosed significantly later than those without elastosis (P approximately 0; log-rank test). This result may be because elastosis is positively related to age. However, I also found that melanomas of head and neck areas, which tend to have more elastosis, were diagnosed at later ages than melanomas of other body sites (P = 1.2 x 10-5; log-rank test). Thus, a second explanation for the results favors a protective effect of elastosis on the development of cutaneous melanoma, possibly related to increased levels of vitamin D. I also found that once melanoma develops, cases with elastosis demonstrated no differences in thickness, mitotic rate, ulceration, or overall survival time from cases without elastosis.