Significant progress has been made in recent years in understanding the origins of cutaneous maligant melanoma. Knowledge of the relationship between solar radiation and melanoma has changed and it now appears that both the character and timing of exposure may be more important than total cumulative dose in accounting for risk. The melanoma-sunlight model may prove an instructive heuristic exercise for environmental epidemiology, as we currently tend to restrict ourselves to a search for uniform total dose--response relationships between cancers and suspected environmental carcinogens. The study of the relationship between acquired melanocytic nevi and melanoma has led to useful new information about predictors of melanoma risk, and in addition has opened new perspectives on the development of nevi in children. Definition of the factors for nevus development in children may lead to the possibility of primary prevention programs for melanoma in younger generations of children. Recent new evidence suggests that certain occupational groups may be at elevated risk of melanoma. A great deal of work is going into the study of ways of screening high risk populations in order to detect melanoma at its earliest stages when current treatment protocols are most effective. The visibility of lesions on the skin challenges classical definitions of early detection and screening in epidemiology.

Interest in the etiology of malignant melanoma has increased enor mously in the last 10 years, after it was realized that the incidence of the cutaneous form of the disease was rising. Treatment of the disease has not improved dramatically, and our best hope for curtailing the rise in mortality and morbidity from the disease appears to be primarily through early detection and, per haps in the future, through prevention. It is thus very important for the medical community to be able to recognize individuals and groups at high risk of the disease because of either familial and con stitutional factors and lifestyle or exposure to environmental risk factors. This book, arising from a meeting held in Vancouver in 1984, pro vides a summary of the latest findings amo ~ Caucasian popula tions along with perspectives on the most im, Jrtant environmental risk factors identified to date. Comparison of results from the four major analytic studies presented here also demonstrates that a num ber of factors implicated in other common cancers are probably not related to the incidence of melanoma. These include smoking, alco hol consumption, and for the most part, diet. The Vancouver conference was sponsored by the Cancer Control Agency of British Columbia, and was financially supported by Health and Welfare Canada (6610-1429-50), the Northern Califor nia Cancer Program (NCCP), Miles Laboratories (Canada), Bristol Myers Laboratories (Canada), and Plough Canada Inc.