Increase in basal cell carcinoma incidence steepest in individuals with high socioeconomic status: results of a cancer registry study in the Netherlands

Background Development of both basal cell carcinoma (BCC) and cutaneous malignant melanoma (MM) is associated with acute and intermittent sun exposure. In contrast to MM, the association between socioeconomic status (SES) and BCC is not well documented. Objectives To investigate the incidence of BCC according to SES, stratifying by age and tumour localization in a large population-based cohort. To assess changes over time in the distribution of the patients with BCC across the SES categories. Methods All patients with a histologically confirmed first primary BCC (n = 27 027) diagnosed between 1988 and 2005 in the Southeast of the Netherlands were stratified by sex, age (25-44, 45-64 and 65 years), period of diagnosis, SES category (based on income and value of housing) and localization of the BCC. Age-standardized BCC incidence rates were calculated for the year 2004 by SES category and localization. Ordinal regression was used to assess changes over time in the proportion of patients with BCC by sex, age and SES. Results For men in all age groups higher BCC incidence in the highest SES category was observed, which remained significant after stratification for tumour localization. For women a consistent relationship was found only in younger women (< 65 years) for truncal BCCs, which occurred more frequently in high SES groups. Between 1990 and 2004, the proportion of BCC patients with high SES increased (+ 6%) and the proportion with low SES decreased (-7%). Conclusions High SES is associated with increased incidence of BCC among men. Our data suggest that BCC is changing from a disease of the poor to a disease of the rich