AT WHAT AGE DO SUNBURN EPISODES PLAY A CRUCIAL ROLE FOR THE DEVELOPMENT OF MALIGNANT-MELANOMA

The age relationship between sunburns and malignant melanoma was inves tigated in a population-based, matched, case-control study from the So uth Swedish Health Care Region (the highest risk area for melanoma in Sweden). Between 1988 and 1990, a total of 400 patients with a first d iagnosis of malignant melanoma and 640 healthy controls aged 15-75 yea rs answered a comprehensive questionnaire including questions regardin g ultraviolet radiation exposure. In addition, a literature review was performed. The average number of episodes of sunburn per year was sig nificantly associated with malignant melanoma (relative risk, RR = 1.9 for greater than or equal to three episodes per year versus never). O utdoor employment during the summer was associated with a decreased ri sk for the development of malignant melanoma (RR = 0.8). Data from cas e-control studies and migration studies concerning age relationship be tween sunburns and melanoma are inconsistent. From our own data, we di d not find a higher risk of melanoma developed in individuals who had experienced severe sunburns in childhood. Instead, a significantly inc reased risk was associated with sunburns after age 19 years, RR = 2.2 for a history of more than five times versus never. Even if the hypoth esis is biologically plausible, that episodes of sunburn early in life are associated with a higher risk of melanoma, so far epidemiological evidence is scarce. There is a need for better prospective epidemiolo gical studies addressing this issue.