Multiple primary malignancies in patients with cutaneous melanoma

Abstract

Two hundred and ninety five Caucasian patients with histologically confirmed primary cutaneous malignant melanoma were evaluated. Twenty‐three primary non‐melanocytic, non‐cutaneous malignant tumors occurred in 22 patients with a single primary cutaneous malignant melanoma for a prevalence of 8.2% (23/281). The observed number of non‐melanocytic, non‐cutaneous malignant neoplasms did not differ significantly from the expected number calculated on the basis of patient years at risk. Melanoma patients with primary non‐melanocytic, non‐cutaneous tumors were significantly older at the time of diagnosis of their melanoma than patients with melanoma alone. In addition, patients with multiple primary tumors were at risk a significantly longer period of time. With the possible exception of breast cancer, the association of cutaneous melanoma and additional non‐melanocytic, non‐cutaneous malignancies appears to be a random event. Nine additional primary cutaneous malignant melanomas were confirmed in eight melanoma patients for a prevalence of 3.4% (9/267). The observed number of additional primary melanomas was significantly greater than the expected number calculated on the basis of patient years at risk. Patients with multiple primary melanomas were not at risk significantly longer than patients with only one melanoma. It is likely that the development of additional primary melanomas in patients with an initial melanoma is not simply a random event, but represents a greater susceptibility of these patients' melanocytes to malignant transformation. Copyright © 1977 American Cancer Society