A cancer registry-based analysis on the non-white populations reveals a critical role of the female sex in early-onset melanoma

Purpose Most melanoma studies have been performed in the white population who exhibits the highest incidence rate due to their skin sensitivity to UV radiation. Previous publications have shown that young women (approximately under the menopausal age) exhibit higher incidence rates than men of the same age, and the causes are mostly attributed to their sun behavior or indoor tanning. In our recent publications, we suggested that higher risk in younger women was due to pathophysiological factors, such as hormonal impact, and thus this higher risk in young women should be shared across ethnicities regardless of their skin color or UV behavior. Methods A total of 13,208 non-white melanoma patients from SEER and 15,226 from WHO CI5-Plus were extracted for analysis. Age-specific incidence rates, female-to-male incidence rate ratios, and p values were calculated. Results As observed in the white population, younger women and older men showed higher melanoma incidence rates than their peers of the other gender in all ethnic groups. The highest female-to-male incidence rate ratios were observed in the pubescent and reproductive ages. Previously this gender discrepancy in the white population was attributed to the preference of skin tanning in young females. There is no evidence to show that darker-skinned young females adopt a similar tanning preference. Thus the age-dependent gender difference in the risk of melanoma is shared across ethnic groups and is perhaps independent of UV behavior. Conclusions Our results highlight the importance of gender as one of the melanoma risk factors beyond traditional UV radiation, which warrants further investigation and may provide a base for an improved prevention strategy.