[Effect of mitotic density on the probability of survival of patients with thin (less than or equal to 1.5 mm) melanomas].

Our studies dealt with the prognostic significance of the mitotic count for patients with thin (less than or equal to 1.5 mm) melanoma. We determined the mitotic rate of 50 patients who had died of melanoma thinner than 1.5 mm within 8 years (short-term survivors). The specimens were examined by means of a rectangular visual field; thus we could calculate the mitotic count to the square mm of the tumor surface. This outcome was compared to the mitotic rate of 50 long-term survivors who had not died within 8 years and who corresponded to the first group with regard to sex, tumor thickness, as well as tumor site. In both groups, at least 15% of the melanomas did not show any mitotic figure. With females, the average mitotic values were identical in both groups (1.1 vs. 1.15). In males, however, short-term survivors revealed a significantly (p less than 0.001) higher mitotic count (2.2) than long-term survivors (0.75).