Cytometry and morphometry of malignant fibrous histiocytoma of the extremities. Prediction of metastasis and mortality.

Flow cytometry and nuclear morphometry were compared with traditional pathologic grading techniques for predicting the course of malignant fibrous histiocytoma of the extremities. Clinical, pathologic, and flow/morphometric variables from 53 cases were tested by Cox regression for prediction of distant recurrence and mortality. Tumor grading based on extent of tumor necrosis was a significant predictor for both disease-free survival (p = .014) and overall survival (p = .003). The fraction of nuclei in the S + G2M segment of DNA histograms was significant for disease-free survival (p = .007), and remained significant (p = .033) in a joint Cox model with necrosis-based grade (p = .004 for the bivariate model). Relative risk for recurrence varied nearly 10x between the 10th and 90th percentiles of grade and (S + G2M)1/2. Overall survival was predicted by a nuclear shape feature termed "R" (p = .000008), the casewise difference (residual) between expected and observed nuclear perimeter as a function of average Feret diameter. In a bivariate Cox model, relative risk of mortality varied 35x between the 10th and 90th percentiles of grade and R. Cytometric and morphometric data contain information about recurrence-free and overall survival beyond that available from more usual clinical and pathologic features. It seems likely that nuclear morphometry, in particular, will prove to be a useful aid for estimating the prognosis of patients with malignant fibrous histiocytoma of the extremities.