Cutaneous malignant melanoma in Rochester, Minnesota: trends in incidence and survivorship, 1950 through 1985.

In Rochester, Minnesota, 107 incidence cases of cutaneous malignant melanoma (in 46 male and 61 female patients) were diagnosed during the years 1950 through 1985. Overall crude incidence rates were 6.0 and 6.6 per 100,000 males and females, respectively. Evaluation of trends in 9-year periods showed that the rates increased from 3.2 to 8.9 for males (P = 0.015) and from 4.4 to 11.7 for females (P less than 0.001). Age-specific rates suggested that the highest incidence occurs in the age-groups 50 to 59 years and 70 years or older for males and 40 to 49 years and 70 years or older for females. Lesions were most common in the head and neck area among males (P = 0.044) and on the lower extremities among females (P = 0.018). The most frequent histologic type was superficial spreading melanoma (61%). Five-year survival was diminished overall for patients with cutaneous malignant melanoma--0.72 in comparison with 0.88 expected for the general population. Statistically significant risk factors for survival were depth of invasion of the lesion (Clark level), thickness of the lesion, histologic type, and age of the patient.