Malignant melanoma in Connecticut and Denmark.

The rising incidence of malignant melanoma of the skin was reviewed using data from the Connecticut Tumor Registry (1935-1974) (Eisenberg et al., 1967) and the Danish Cancer Registry (1942-1972) (Clemmesen, 1965, 1974, 1977). A total of 7,530 cases were analyzed according to age, sex and anatomic site. The total age-adjusted incidence rates were similar for these two countries, despite geographic and demographic differences. HOwever, the most rapid changes in melanoma incidence were observed in females from Denmark and males from Connecticut. In addition, the largest increases occurred for lower-extremity lesions in Danish middle-aged women and trunk-neck melanomas in Connecticut middle-aged men. Melanoma of the face was resistant to changing incidence and occurred in an older age group than melanoma of other skin sites. In general, birth cohort analysis confirmed that changing incidence began for persons born around 1900, but the rising incidence for lower-extremity melanomas in women and trunk-neck melanomas in males began earlier. In comparing incidence for anatomic sites by correcting for surface area and melanocyte density, higher than expected rates were seen for melanoma of the face in both sexes and trunk-neck melanoma in the males. The data presented support the concept that a cumulative exposure to solar radiation may be important in the etiology of melanoma of the face, but short-, intense sun exposure is probably related to melanoma in other sun-exposed areas, and that melanoma in areas other than the face is responsible for the rising incidence of this disease.