Basal cell carcinoma: an emerging epidemic in women in Iceland*

Abstract

Background An epidemic of BCCs has led to a significant healthcare burden in Caucasian populations. Objectives To provide an update on incidence‐rates and tumor‐burden in an unselected, geographically isolated population that is exposed to a low level of UV radiation. Methods A whole population study using a cancer registry containing records of all BCC cases in 1981‐2017. We assessed BCC incidence according to age, residence and multiplicity and assessed trends using joinpoint‐analysis. Age‐standardized and age‐specific incidence rates were calculated along with cumulative and lifetime‐risks. Results Throughout the study period, the age standardized incidence rates increased from 25.7 to 59.9 for men, and from 22.2 to 83.1 for women (per 100.000). Compared to the single tumor‐burden, total tumor‐burden in the population was 1.72 times higher when accounting for multiplicity. In 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 (83.1, 95% CI [77.9‐88.3]) compared to men (59.9, 95% CI [55.6‐64.2]). This increase was most prominent in women years on sites that are normally not exposed to UV radiation in Iceland, the trunk and legs. Conclusions This is the only reported population in which the incidence of BCC is significantly higher in women than in men. The period of notable increase in BCC lesions correlates with the period of increase in tanning bed and travel popularity. The high multiplicity rates suggest that total tumor burden worldwide might be higher than previously thought.