Prognostic influence of HSP-27 expression in malignant fibrous histiocytoma: a clinicopathological and immunohistochemical study.

Malignant fibrous histiocytoma is a very aggressive sarcoma. After the tumor has disseminated, chemotherapy is of little influence on the course of the disease because of the resistance to most chemotherapy regimens. We evaluated by immunohistochemistry the prognostic influence of the expression of a member of the stress polypeptides family, the heat-shock protein of 27 KDa (HSP-27). HSP-27 was found to be associated with an aggressive behavior in breast carcinoma and was related to chemoresistance in cell cultures. Forty-three malignant fibrous histiocytomas with no evidence of metastases at the time of diagnosis and resected between 1974 and 1985 were retrieved from the files of the Pathology Department of L'Hôtel-Dieu de Québec hospital. The immunostaining was performed on Bouin-fixed, paraffin-embedded tissue. Regardless of the percentage of positive cells, HSP-27 was expressed in the cytoplasm of 25 (58.1%) cases. HSP-27 expression was associated with a more favorable prognosis, and a significant correlation was observed with overall survival (P less than 0.025) and metastasis-free survival (P less than 0.05). HSP-27 expression was found to be the strongest prognostic factor, and multivariate analysis revealed that it was independent of tumor size, necrosis, and histological subtype. However, in the 13 patients with recurrent disease who underwent chemotherapy, the antigenic expression did not help to predict the treatment response. HSP-27 expression is one of the rare prognostic markers in this tumor type.