Basal cell carcinoma: an emerging epidemic in women in Iceland

Background An epidemic of basal cell carcinoma (BCC) has led to a significant healthcare burden in white populations. Objectives To provide an update on incidence rates and tumour burden in an unselected, geographically isolated population that is exposed to a low level of ultraviolet radiation. Methods This was a whole-population study using a cancer registry containing records of all cases ofBCCin 1981-2017. We assessedBCCincidence according to age, residence and multiplicity and assessed trends using join-point analysis. Age-standardized and age-specific incidence rates were calculated along with cumulative and lifetime risks. Results During the study period, the age-standardized incidence rates increased from 25 center dot 7 to 59 center dot 9 for men, and from 22 center dot 2 to 83 center dot 1 for women (per 100 000). Compared with the single-tumour burden, the total tumour burden in the population was 1 center dot 72 times higher when accounting for multiplicity. At the beginning of the study period, the world-standardized rates in men and women were similar, but by the end of the study period the rates were 39% higher in women (83 center dot 1 per 100 000, 95% confidence interval 77 center dot 9-88 center dot 3) than in men (59 center dot 9 per 100 000, 95% confidence interval 55 center dot 6-64 center dot 2). This increase was most prominent in women on sites that are normally not exposed to ultraviolet radiation in Iceland: the trunk and legs. Conclusions This is the only reported population in which the incidence ofBCCis significantly higher in women than in men. The period of notable increase inBCClesions correlates with the period of an increase in tanning beds and travel popularity. The high multiplicity rates suggest that the total tumour burden worldwide might be higher than previously thought.