Immunohistochemical detection of HER-2/neu, c-kit (CD117) and vascular endothelial growth factor (VEGF) overexpression in soft tissue sarcomas.

PURPOSE: The aim of this study was to determine the incidence of HER-2/neu, VEGF and CD117 overexpression in soft tissue sarcomas (STS) and to study the effect of this overexpression, if present, on survival in patients with specific histological subtypes of STS. MATERIALS AND METHODS: We conducted a retrospective observational study on patients diagnosed with STS during the period of 1986-2001. HER-2/neu overexpression was measured in these patients by immunohistochemistry (IHC) using the Hercep test developed by DAKO. VEGF expression was detected by the avidin-biotin-complex method using Santa Cruz biotechnology (SC 7629). Immunohistochemical staining for c-kit was performed using a 1:250 dilution of the rabbit polyclonal antibody A4502 (IMPATH, CA) with the EnVision detection system. RESULTS: Two hundred and seventy three patients were diagnosed as having STS between 1986 and 2001, however of these patients, only 90 (51 females and 49 males) had enough sample available for testing. Patients who overexpressed VEGF had a significantly shorter survival (23 vs. 52 months; p=0.01). There was no effect of overexpression of either CD117 or HER-2/neu on survival. Studying the individual histological subtypes we found that, in malignant fibrous histiocytoma, overexpression of either VEGF or CD117 increased survival (41.3 vs. 19.5 months, p=0.01; and 84.5 vs. 17 months, p=0.006 respectively). In leiomyosarcoma, VEGF overexpression significantly decreased survival (7.5 vs. 76 months, p=0.03), while CD117 overexpression significantly increased survival (70.9 vs. 46.3 months, p=0.03). CONCLUSION: VEGF overexpression is associated with an adverse outcome in STS. Whether this is true of any particular histological subtype is unclear and needs further investigation. Also, site-specific agents targeting these three bio-markers (alone or with conventional therapy) may have a therapeutic role and need to be elaborated in future clinical trials.

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

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.