Sociodemographic factors and incidence of melanoma in the Netherlands, 1994-2005

Background: Time-space incidence maps of the Netherlands indicated differences in incidence of cutaneous melanoma (melanoma) over the country, which might be related to sociodemographic characteristics of living environment and socioeconomic status (SES) of the patients. The goal of this study was to refine the current approaches to prevention and early detection of melanoma by revealing relationships between sociodemographic factors and incidence of melanoma in the Netherlands. Methods: Age-adjusted incidence rates were calculated from the Netherlands Cancer Registry. Data on sociodemographic factors were obtained from Statistics Netherlands. Logistic regression analysis was performed to investigate determinants of variation in incidence at the ecological level. At the individual level tumour characteristics were linked to SES based on postal code at the time of diagnosis. Results: The lowest SES-group had a significantly lower incidence than the highest SES-group; 10.2 (95% confidence intervals (CI): 9.1-11.3) and 14.3 (95% CI: 12.9-15.8), respectively. Increased risk of melanoma was seen in municipalities with high population density, few people living on social security and many people with high income. Patients living in low SES neighbourhoods were diagnosed more often with higher stage disease (13% (95% CI: 12.3-13.8) diagnosed with pT4) than those living in high SES neighbourhoods (9% (95% CI: 8.5-9.8) diagnosed with pT4) (p < 0.001) and with higher Breslow thickness (p < 0.001). Conclusions: Awareness of the risks of UV radiation (UVR) is important and in the higher SES-groups primary prevention should remain the focus. However, if the incidence rates for the higher SES-groups are illustrative for the lower SES-groups, then the focus should be on both primary and secondary prevention in the low SES-groups.