Melanoma and sunburn.

A computer-aided search identified 16 case-control studies which specifically assessed sunburn as a risk factor for cutaneous malignant melanoma. Using unadjusted estimates, a history of sunburn was associated with significantly increased risk of melanoma in all but one study. Four studies were defined as core studies after assessment of study quality; however, only two of these had sufficiently similar definitions of sunburn to allow pooling of results. Using pooled data, the risk of melanoma in those ever sunburned was 2.0 (95 percent confidence interval [CI] = 1.6-2.6), while the highest category of sunburn exposure had a risk of 3.7 (CI = 2.5-5.4). The suggestion that sunburns in childhood carry greater risk of melanoma cannot be supported by pooled analysis. This review demonstrated considerable variation in design and method among the studies, and identified sources of bias which prevented a pooled analysis using all available data. The need for strong epidemiologic evidence relating sunburn to melanoma, particularly in childhood, is of prime importance, since avoidance of sunburn is one of the few potential means of primary prevention of melanoma.