Skin cancer. Melanoma and other specific nonmelanoma skin cancers.

BACKGROUND: Malignant melanoma accounts for most of the growing mortality from skin cancer. However, survival rates are increasing for individual cases, probably because of earlier diagnoses.

METHODS: Skin cancers collected by the SEER population-based data base between 1973 and 1987 are described in terms of their histologic classification and their distribution by sex, race, anatomical location, geographic locality, and time period of occurrence.

RESULTS: There were 30,519 invasive skin cancers in the 15-year reporting period. Because the common basal cell and squamous cell cancers are not reportable to SEER, most of the cancers (28,206) were melanomas. In addition, 4386 in situ melanomas were reported. The rate of melanoma was 13-fold higher in whites than in blacks and 29% higher in white males than in white females. There was a 52% increase in the age-adjusted incidence rate for invasive melanoma and a 600% increase in the incidence rate of in situ melanoma over the 15-year period for whites and a 12% decrease in the incidence rate of invasive melanoma in blacks. The incidence of melanoma in the ear and trunk predominated in males, whereas melanoma of the lower limb predominated in females. Incidence rates and rate of increase of incidence of melanoma varied by anatomical subsite, sex, and geographic location within the United States.

CONCLUSIONS: The variations among incidence rates of melanoma by sex, subsite, race, geographic location, and time period support prevailing theories of a solar cause for most but not all cases of this disease. Although melanoma rates are rising overall, the disproportionate rise in the rate of diagnosis of in situ compared with invasive melanoma suggests that melanomas are being diagnosed earlier.