Prognostic significance in malignant melanoma of nuclear DNA content measured by a microfluorimetric method.

The nuclear DNA content of 47 primary malignant melanomas was measured by 4',6-diamidino-2-phenylindole-DNA (DAPI-DNA) microfluorimetry, and the DNA index, a quantitative measure of nuclear DNA content, was calculated. The DNA index and other clinical and pathological variables were examined and compared with patient survival using univariate and multivariate analyses. The Kaplan-Meier life table method revealed that the DNA index and metastases to regional lymph nodes significantly correlated with patient survival. A Cox proportional hazards multivariate analysis demonstrated that the DNA index, which was not significantly correlated with other variables, was the most reliable and independent factor for predicting patient survival.