Introduction: Melanomas arising in areas with comparable levels of sun exposure have been shown to have similar genetic profiles. The aim of this study was to characterize the clinical features of melanoma patients according to the pattern of sun exposure: chronic, intermittent, or none.
Material and methods: From our melanoma database, we selected 789 consecutive patients with melanoma diagnosed in our center since January 2000. Epidemiologic data, phenotype, and personal and family history of cancer were retrieved. The observed frequency of each variable was compared.
Results: Most melanoma patients presented tumors on areas exposed intermittently to sunlight. In addition, these patients presented higher numbers of common and atypical melanocytic nevi and the melanoma very frequently arose in a pre-existing nevus. The second largest group was formed by patients with tumors on areas chronically exposed to sun and that had all the clinical lesions (solar lentigines and actinic keratoses) and epidemiological characteristics typical of these areas. Finally, patients with melanomas on areas not exposed to sun were older, as occurred in the group with chronic exposure, and the diagnosis was made at more advanced stages of the disease.
Conclusions: There are many patients who did not fit these patterns of melanoma development. Clinical and biological characterization is therefore necessary to determine alternative pathways of development in order to establish specific preventive measures.