Proliferating cell nuclear antigen staining as a prognostic indicator in soft-tissue malignant fibrous histiocytoma.

To determine the value of proliferating cell nuclear antigen (PCNA) staining as a prognostic indicator in soft-tissue malignant fibrous histiocytoma (MFH), we studied 27 patients who underwent resection including an adequately wide margin but without chemotherapy. The survival rate of patients with a lesion in which less than 70% of the cells was positively stained was significantly higher (P < 0.01) than of those with more than 70% positive staining. Twenty-two patients (81.5%) evidenced disease-free survival (mean follow-up period 4.6 years), 1 patient was alive with disease, and 4 (14.8%) died of the disease with lung or lymph node metastasis. In all 4 patients who died, PCNA staining was over 70% positive. In 2 of them, an increase in the number of PCNA-positive cells was observed after repeated recurrence. We conclude that PCNA is a useful prognostic indicator which provides a quantitative measure of the grade of malignancy in MFH patients who receive operative treatment without chemotherapy.