Sex differences in the association of cutaneous melanoma incidence rates and geographic ultraviolet light exposure

Abstract

Background Cutaneous melanoma (CM) incidence rates continue to increase, and the reasons are unknown. Previously, we reported a unique age-specific gender difference in melanoma that suggested additional causes other than solar UV radiation. Objective This study attempted to understand whether and how UV radiation differentially impacts the CM incidence in men and women. Methods CM data and daily UV index (UVI) from 31 cancer registries were collected for association analysis. A second dataset from 42 states of the U.S.A. was used for validation. Results There was no association between log-transformed female CM rates and levels of UVI but there was a significant association between male rates and UVI and a significant association between overall rates and UVI. The 5 year age-specific rate-UVI association levels (represented by Pearson’s coefficient ρ) increased with age in men, but age-specific ρ levels remained low and unchanged in women. The significant rate-UVI association in men and non-association in women was validated in the US white population. Limitations Confounders including temperature and latitude are difficult to separate from UVI Conclusions: Ambient UVI appears to be associated with melanoma incidence in males but not in females.

Increasing incidence of lentigo maligna and lentigo maligna melanoma in Catalonia

“…No significant differences were found. The higher incidence of LM/LMM among women vs. men in both Dutch series and ours suggests a possible role of chronic sun exposure of facial female skin for recreational or tanning purposes as a risk factor, unlike other previously reported data…”

“…Regarding gender differences in the association of melanoma incidence rates and ultraviolet light exposure, Liu‐Smith et al . performed an ecologic study involving different countries that provide evidence that melanoma rates are associated with ultraviolet light index (UVI) in males but not in females and that the levels of association between male rates and UVI increase with age, supporting the idea that the etiology of melanoma in older age groups was largely attributable to cumulative UV exposure.…”

Trends in the incidence of Merkel cell carcinoma in Victoria, Australia, between 1986 and 2016

“…However, this study reported that these results were not evident in Northern American women or European countries studied. The UV index is generally higher in Queensland than in Victoria, and this could contribute to the differences in incidence seen between the two Australian states …”

“…The UV index is generally higher in Queensland than in Victoria, and this could contribute to the differences in incidence seen between the two Australian states. 18,19 Besides chronic ultraviolet light exposure, the Merkel cell polyomavirus (human polyomavirus 5) is also thought to play a role in the formation of MCC. The polyomavirus clonally integrates into the genome of cells, which allows for virally induced transformation into MCC.…”

Clinical features and outcome of dermal squamous cell carcinoma in 193 dogs (1987‐2017)

“…Although it was ultimately not statistically significant on multivariate analysis, there may have been an inherent bias given the methodology used to calculate MI (using the highest reported value) and a protective benefit of a low MI may have been missed. Lastly, the geographic location of affected animals in California with chronic exposure to solar UV exposure may not replicate the findings in other geographic locales with fewer sunny days …”