Cyclooxygenase-2 expression is not associated with clinical outcome in synovial sarcoma

Several studies have identified cyclooxygenase-2 (COX-2) expression in a variety of sarcomas, including rhabdomyosarcoma, osteosarcoma and chondrosarcoma. Although overexpression of COX-2 has been associated with poor prognosis and decreased survival in chondrosarcoma and osteosarcoma, no relationship between COX-2 expression and patient outcome has been demonstrated in rhabdomyosarcoma or adult soft tissue sarcomas. Little is known concerning the expression of COX-2 in synovial sarcoma. Therefore, the aim of this study was to examine the expression of COX-2 in synovial sarcoma and if shown, to identify any association with tumor stage and oncologic outcome. Paraffin-embedded specimens from 27 patients with synovial sarcoma who were treated with surgical resection or biopsy were obtained. Specimens were evaluated for the degree of COX-2 expression after immunohistochemical staining. Specimens were assigned an immunoreactivity score (IS) based on the percent positivity of the specimen. A retrospective chart analysis was performed to determine the clinical stage at presentation, incidence of local recurrence, presence of metastatic disease and overall survival. Statistical analysis was then performed to determine whether there was a significant relationship between IS and stage at presentation or patient outcomes. COX-2 expression was detected in 18 of 27 (66.67%) of the pathological specimens. There was a statistically significant relationship between COX-2 expression and patient clinical stage at presentation; however, we were unable to identify a significant relationship between IS and patient survival. We also found no significant relationship between IS and development of metastases or local recurrence. COX-2 was expressed to some degree in 67% of the tumor specimens. There was a significant relationship between IS and patient stage at presentation, but no significant relationship between COX-2 expression and clinical outcome could be identified. The fact that these tumors do express COX-2, however, suggests the potential for an additional target for more effective therapy.