Cutaneous melanoma in women. II. Phenotypic characteristics and other host-related factors.

A total of 452 women with cutaneous malignant melanoma and 930 control subjects aged 25-59 years participated in a population-based case-control study carried out in the San Francisco Bay Area between 1981 and 1986. Interviews were conducted in the homes of the women. Questions were asked about various phenotypic characteristics, including eye, hair, and complexion color, presence of freckles, and number of nevi, as well as medical history, history of exposure to sunlight, ability to tan, occupation, use of cigarettes and alcohol, and demographic factors. Histologic type of melanoma was considered in the analysis: 355 (79%) women were diagnosed with superficial spreading melanoma, 61 (13%) had nodular melanoma, 13 (3%) had lentigo maligna melanoma, and 23 (5%) had other melanomas that could not be further classified. For all cutaneous melanoma subjects combined, univariate results related to host factors showed that risk increased with the presence of nevi greater than 5 mm in diameter; light eyes, hair, and complexion; freckles; a history of skin cancer other than melanoma; a history of skin cancer in relatives; and maternal and paternal Northern or Central European ancestry. After adjustment for each other and for sun exposure factors, the phenotypic and host factors associated with all types of cutaneous malignant melanoma and superficial spreading melanoma were the presence of large nevi, light hair color, light complexion, and maternal Northern or Central European ancestry. Host factors associated with nodular melanoma after adjustment for other factors were the presence of large nevi, light hair color, ever being overweight by 20 pounds (9 kg) or more, and the presence of freckles.