Clustering of cutaneous melanoma in health care workers of a dermatological day hospital unit.

BACKGROUND: The incidence of cutaneous melanoma is increasing but in most countries is still below 20/100,000 per year. Despite such a low frequency of occurrence, recently the authors have had notice of several new melanoma cases among colleagues. We carried out a survey of melanoma occurrence among the personnel, and their close relatives, of a dermatological clinic. The self-reported figures were compared with data from cancer registries. OBSERVATIONS: Thirty-eight doctors and nurses were surveyed. Three responders reported having had a diagnosis of melanoma (7.9%, 95% CI 1.7-21.4%). The respondents reported having 617 'relatives who are alive today and would have come to them if they had a melanoma': 12 had known diagnoses of melanoma (1.9%, 95% CI 1.0-3.4%). The relative risks were 26.3 (95% CI 8.9-78.0) and 4.1 (95% CI 1.2-13.8) for doctors and nurses compared to the general population and to their relatives, respectively, and 6.5 (95% CI 3.7-11.4) for relatives compared to the general population. CONCLUSIONS: Two nonmutually exclusive hypotheses may be formulated to explain these findings: (a) most cutaneous melanomas regress spontaneously; (b) an infectious agent is involved in the causal pathway of cutaneous melanoma. Further studies may be warranted to confirm our observations and test such hypotheses.