Incidence and trends of basal cell carcinoma in Sweden: A population-based registry study

BACKGROUND: Basal cell carcinoma (BCC) is the most common skin cancer. Incidence is largely unknown because of incomplete, or lack of, registration in most countries.

OBJECTIVES: To assess current incidence rates and recent trends for BCC in the Swedish population.

METHODS: Patient- and tumour-related features of all histologically confirmed BCC tumours diagnosed in Sweden from 2004 to 2017 were extracted from the population-based Swedish BCC Registry. Incidence rates were standardized to the 2013 European Standard Population and trends were analysed using Poisson regression models.

RESULTS: Age-standardized person-based incidence rate of BCC in Sweden in 2017 was 405/100 000, rising from 308/100 000 in 2004, corresponding to an annual relative increase of 1.8% (women, 2.1%; men, 1.4%). Incidence was highest in the elderly and the most common tumour site was the head and neck. In 2017, the most common BCC subtypes were nodular and micronodular/infiltrative BCC (each 31%). Incidence of aggressive BCC subtypes increased faster than other subtypes.

CONCLUSIONS: BCC incidence rates in Sweden are relatively high and increasing. The increasing trends were more pronounced in women and for aggressive BCC subtypes.