Cancer cell-expressed immunoglobulins: CA215 as a pan cancer marker and its diagnostic applications

Background: RP215 was the first generated monoclonal antibody which recognizes specifically carbohydrate-associated epitope(s) localized in the variable region of the cancer cell-expressed immunoglobulin heavy chains, designated in general as CA215. Clinical evaluations were performed to assess if RP215 can be utilized in immunoassays to determine serum levels of CA215 among ovarian or cervical cancer patients for monitoring purposes. Methods: By using immunoassays, serum CA215 levels were determined from cervical or ovarian cancer patients and evaluated based on their respective clinical stages as well as the conditions of clinical treatments. Results: Multi-center clinical trials were performed with frozen serum specimens of patients with ovarian or clinical cancers to determine the efficacy of RP215-based immunoassays. In the case of ovarian cancer, CA215 immunoassay kit has a sensitivity of 46-68% as compared to 46-70% for that of the corresponding CA125 kit. When both markers were combined for simultaneous monitoring of cancer patients, the sensitivity could be as high as 72-87%. Further analysis revealed that serum CA215 levels among cancer patients are well correlated with stages of tumor progression as well as surgical or radio/chemo treatments. Conclusions: The results of these multi-center clinical studies suggest that CA215 is a suitable pan cancer marker for the monitoring of ovarian/cervical cancers and maybe of several others which express CA215 and can be detected in human circulations.