On the association between vitiligo and malignant melanoma.

Sir, An unusual and potentially important facet of vitiligo is its relationship to malignant melanoma. The selective destruction of pigment cells that occurs in vitiligo can be regarded as a therapeutic goal sought in melanoma treatment. Thus, the association of vitiligo and melanoma is of special interest to dermatologists, immunologists, and oncologists, and vitiligo can be viewed as an experiment of nature that accomplishes the goal of melanoma immunotherapy. However, the nature of the link between vitiligo and melanoma is not known, although the association has been observed by several investigators in the past (1 ^ 6). The relative rates have also been controversial, ranging from 1.4% (7) to 20% (8). Interestingly enough, the development of vitiligo is claimed to improve the prognosis of melanoma in both man and animals (2, 9 ^ 11) and it has been shown that patients with vitiligo or with melanoma can develop an immune response to identical antigens on pigmented cells and that these antigens are expressed by both melanocytes and melanoma cells (12). So the aim of the present study was to determine the prevalence of malignant melanoma in a population of patients with vitiligo. We included squamous cell carcinomas in the study. Since both melanoma and squamous cell carcinomas are rare, the size of the study population is crucial. Therefore, we linked information from 1052 patients seen for vitiligo during 1970 ^ 1992 at two large dermatological clinics in Stockholm, Karolinska Hospital and Danderyd Hospital, with the compulsory Swedish Cancer Registry to identity individuals among them with melanoma and squamous cell carcinomas.