Cancer surveillance series: role of demographic aspects, altitude and latitude in the extracutaneous malignant melanoma in a residential study.

BACKGROUND: Extracutaneous melanoma (ECM) is a very rare malignancy and its biology differs from that of cutaneous melanoma. Residential studies can offer an important contribution to the study of this disease. METHODS: We characterized the distribution of ECM according to residential and demographic baseline characteristics. We computer-searched patients that removed an ECM, and we analyzed all demographic and residential parameters. Disease free survival (DFS), date of death or last follow-ups were evaluated. The same parameters were analyzed using hazards-regression. Finally, we used the multiple regressions between DFS and the predictors. RESULTS: A total of 44 ECM patients were included in our analysis. Median DFS was of 10 months; at Log-Rank Test and Cox-hazard regression, the variable age (P<0.01; P<0.004) and latitude (P<0.02; P<0.006) reached a statistical significance; at multiple logistic regression, the significance was instead maintained only for the variable age. General OS was of 42 months at Log-Rank Test age (P<0.001), as well as latitude (P<0.006) maintained its significance at hazard-regression. CONCLUSIONS: Demographic and residential aspects can play an important role in the study of this rare disease, supporting the assumption that ECM are generated by processes actually unknown, as demonstrated in our results compared with those of the literature.