Connective Tissue Oncology Society

2001 CTOS Annual Meeting Posters— Pathology

HER2/ERBB2 EXPRESSION IN SYNOVIAL SARCOMA

Dafydd Gareth Thomas¹, Donita L Sanders¹, J Sybil Biermann², Laurence Baker³, Thomas Giodano¹
¹Department of Pathology University of Michigan Medical School, ²Department of Orthopedic Sugery University of Michigan Hospitals, ³Department of Internal Medicine University of Michigan Hospitals

OBJECTIVE: Synovial sarcoma is a high-grade soft tissue sarcoma characterized by a bi-phasic morphology and is associated with a poor prognosis. Most synovial sarcoma posses a specific chromosomal translocation (t(X:18) p11.2;q11.2). Surgery and adjuvant chemotherapy has improved the outcome of local disease, however, management of distant metastasis remains problematic. Accordingly there is a need for alternate adjuvant therapies. The c-erbB2 proto-oncogene encodes the human epidermal growth factor receptor 2 (HER-2/neu), a membrane bound tyrosine kinase, overexpressed in a number of carcinomas.

METHODS: Archival cases of synovial sarcomas (n=16) were assessed for HER-2/neu oncogene expression by standard immunohistochemical techniques.

RESULTS: Eleven of the cases (68%) demonstrated the membranous staining reminiscent of over expression in breast carcinomas. To validate the immunohistochemistry results, RT-PCR using archival material was performed and demonstrated the presence of mRNA for c-erbB2 in 10 of 13 (72%) of cases.

CONCLUSION: These results demonstrate c-erbB2 expression in the majority of synovial sarcoma and suggest treatment with recombinant humanized anti-HER2 monoclonal antibodies may represent an appropriate alternate therapy for patients who have failed conventional therapy.