Invasive cutaneous melanoma in The Netherlands, 1989-1990.

The Breslow or tumour thickness is the most important prognostic factor for survival from cutaneous melanoma. We studied the occurrence of melanoma in relation to tumour thickness and subsite in The Netherlands. Data on all newly diagnosed invasive cutaneous melanomas in the Netherlands Cancer Registry in 1989 and 1990 were used to estimate age and sex-specific incidence rates according to site and depth of tumour invasion. The incidence among women (9.5 per 100,000 person-years) was relatively high compared with other European countries. The predominant site was the trunk among men and the leg among women. After age 70, one-third of the melanomas were observed in the head and neck region. According to data from PALGA, the national computerized archive of Dutch pathology laboratories, 37% of the men and 29% of the women had a melanoma > 1.5 mm thick. Among persons younger than age 60, 26% had a melanoma > 1.5 mm thick, compared with 44% among those 60 years and over. In both registries the absolute and relative risks for a thicker melanoma increased with age, particularly for men. In The Netherlands, preventive measures for population groups with thicker melanomas should be targeted towards men and elderly persons.