Seasons influence diagnosis and outcome of cutaneous melanoma.

The effects of season changes on the diagnosis of cutaneous melanoma have already been concluded; however, its clinical significance has yet to be defined. The aim of this study was to assess the effects of seasons on both the diagnosis and outcome of melanoma. A total of 1258 adult Caucasian Turkish cutaneous melanoma patients who had been treated and followed up in a single tertiary cancer referral center were included in the study. The most frequently affected season was summer (29%) followed by spring (26.6%), autumn (23.1%), and winter (21.3%). Similarly, rate of the patients diagnosed in July compared to January was significantly higher (11% vs 6%). Most of the clinicopathological characteristics were not correlated with seasons. The 5-year overall survival rate was significantly higher for patients diagnosed in August (81%) than other months, and especially January (47%) (P = .002 and P = .0001, respectively). Similarly, the patients of July (65%) survived longer than those of January (P = .02). Furthermore, similar favorable outcomes for summer (70%) compared to other seasons and winter (51%) were shown (P = .005 and P = .001, respectively). In conclusion, there are seasonal fluctuations in diagnosis of melanoma with a peak in summer, and those diagnosed in summer have favorable survival outcomes.