Prognostic significance of hypopigmentation in malignant melanoma.

It has been suggested that the presence of cutaneous hypopigmentation favorably influences the prognosis of patients with malignant melanoma (MM). To examine this possibility, we have compared the actual with the predicted survival of 46 patients with MM and hypopigmentation who were among 1130 patients with MM entered in a long-term prospective study of MM at the New York University Medical Center. The actual average five-year survival rate of the patients with MM and hypopigmentation (86.3%) was significantly better than predicted (74.8%) on the basis of the risk factors present in each patient at the time of entry into the study. The findings suggest that hypopigmentation is a factor that beneficially influences the prognosis of MM, and that the mechanisms that inhibit or destroy normal melanocytes in patients with MM may also slow the growth of this cancer.