Clinical evaluations of a new ovarian cancer marker, COX-1

A monoclonal antibody was generated against an ovarian cancer cell line, OC-3-VGH and was shown to recognize a unique tumor-associated antigen, COX-1 found in ovarian or cervical tumors. COX-1 can be detected in the cultured shed medium of several ovarian/cervical cancer cell lines, and in the sera of ovarian or cervical cancer patients when assayed by a sandwich immunoassay kit employing this monoclonal antibody. Multi-medical centers clinical trials have been conducted since 1989 to evaluate the efficacy of using this immunoassay procedure for the cancer monitoring. In the case of ovarian cancer, COX-1 immunoassay kit has the sensitivity of 68% as compared to 71% for the corresponding CA 125 kit. When both COX-1 and CA 125 kits were combined for the simultaneous monitoring of cancer patients, the sensitivity could be increased to as high as 87%. Further analysis revealed that serum COX-1 levels in cancer patients are correlated with stages of tumor progression. Following the surgical removal of tumors, greater than 50% of the cancer patients showed dramatic and significant decrease of serum levels of COX-1 antigen. The results of these multi-center clinical studies clearly suggested that COX-1 is a suitable marker for the monitoring and diagnosis of ovarian cancer patients, when used alone or in combination with CA 125.