Breslow thickness of cutaneous malignant melanoma in Ravenna (northern Italy) 1981-1990.

The distribution of Breslow's thickness by sex, age and site of 95 of the 103 cases of primary cutaneous malignant melanoma (CMM) diagnosed in 1981-1990 in the Ravenna Health District (a low-incidence area in northern Italy) was studied. The median patient age was 57 years. The median tumor thickness was 1.33 mm in females and 2.15 mm in males (two-tailed Wilcoxon rank sum test, p = 0.153). Significantly thinner lesions were found among women up to the median age than among men of the same age group (1.05 mm vs. 1.80 mm, p = 0.034) and older women (2.20 mm, p = 0.035). The difference between males aged under 57 years and older than 57 was not significant (1.80 mm vs. 2.20 mm, p = 0.828). As a consequence, younger women compared favorably with the rest of the population as a whole (2.20 mm, p = 0.011). No significant differences in site-specific median tumor thickness were found between the sexes or between young and older males, whereas CMMs of the legs among females were thinner in the younger age group (0.67 mm vs. 2.20 mm, p = 0.007). The prevalence of younger women in the recognition of early CMM was entirely accounted for by a substantial shift observed in the most recent 5-year period (from 2.40 mm to 0.70 mm, p = 0.006). Specific educational activities have never been carried out in Ravenna.