Melanoma is the third most common cancer in Australia. Naevus-count and sun damage are important risk factors. Studies have revealed sex-specific photodamage and naevus distribution patterns in the general population, however, further research is required in melanoma high-risk individuals. In this study, we investigated sex-specific patterns of photodamage and naevus distribution on the back of high-risk melanoma participants.
3D-total-body photography images of 52 participants with high naevus-count were selected from a melanoma high-risk group. The relationship between sex and photodamage level, and sex and naevus distribution were assessed using Fisher’s exact test and multiple regression models, respectively.
Males showed higher counts of naevi ≥2mm in diameter compared to females (81 (10–296) and 45 (6–181), respectively, p-value 0.010). Naevi ≥5mm, were mostly distributed over the upper-back, with females having a higher proportion of naevi in this area (females 48%, males 36%, p-value <0.001) preferentially located on the upper-right region (females 23%, males 16%, p-value <0.001). Interestingly, both males and females had moderate photodamage on the upper-back (79%), with the only sex-specific difference being mild photodamage in the lower-back seen in 86% of females versus 63% of males.
This study showed a sex-specific distribution of naevi on the back of participants at high-risk of melanoma, which is not associated to differences in photodamage. These findings highlight the importance of further research into sex-specific photodamage and naevus distribution patterns in melanoma high-risk populations to better understand carcinogenesis and improve patient-specific sun-safety advice as well as patient-centred skin-cancer screening.