HER-2/neu overexpression detected by immunohistochemistry in soft tissue sarcomas.

ABSTRACT

Sarcomas currently represent 1% of adult malignancies and 15% of pediatric malignancies. To determine the prevalence of HER-2/neu overexpression by the histologic type and to identify a possible predictive role in patients with sarcoma, we performed a retrospective study on subjects with a biopsy-proven diagnosis of a soft tissue sarcoma. HER-2/neu overexpression was evaluated using immunohistochemistry (IHC) performed on paraffin-embedded specimens. An IHC score of 2+ or greater was considered positive for overexpression. Two hundred seventy-three patients with soft tissue sarcoma were identified (164 females, 109 males) with a mean age of 56 (range 1-93). The most common tumors identified were malignant fibrous histiocytoma (MFH) (18.3%), dermatofibrosarcoma (DFS) (16.1%), leiomyosarcoma (13.2%) and carcinosarcomas (CS) (7.3%). Of the 273 specimens, 29 (10.6%) revealed HER-2/neu overexpression. CS, MFH, and DFS specimens showed the highest incidence of HER-2/neu overexpression (40%, 26%, and 18.2%, respectively). The incidence of HER-2/neu overexpression was found to be significantly higher in patients with a survival of less than 8 months (p = 0.035). This demonstrates that HER-2/neu overexpression is preferentially seen in certain soft tissue sarcomas, and when present is associated with a poorer prognosis in patients with sarcoma. Further studies would delineate whether HER-2/neu overexpression renders sarcomas chemoresistant and thus adversely affects outcome. In addition, there may be a role for Herceptin (trastuzumab) alone, or in combination with conventional therapy, in patients with CS, MHF, and DFS.