Nuclear DNA, serum sialic acid and measured depth in malignant melanoma for predicting disease recurrence and survival.

In a previous multivariate analysis of 151 malignant melanoma patients we identified measured depth of primary lesion (Breslow) and serum N-acetyl-neuraminic acid (NANA) concentration as significant independent predictors of recurrence. Our present study examines the contribution of flow cytometric DNA analysis to prediction of recurrence and survival. Fixed, paraffin-embedded specimens of primary lesions were evaluated from 63 of the previously studied patients. These were prepared for DNA analysis. Of the 28 primaries identified as aneuploid 17 later recurred, while this was true for only 9 of the 35 diploid tumors. On multivariate analysis measured depth was again the most significant predictor of recurrence (p less than 0.001). Additional independent predictors were DNA ploidy (p = 0.02) and NANA (p = 0.05). For survival the independent predictors were measured depth (p = 0.003) and NANA (p = 0.05). Measured depth, DNA ploidy and NANA can be used to construct a model predicting the recurrence risk for stage-I melanoma.