Polyclonal antitumor immunoglobulin may play a role in ovarian cancer adjuvant therapy

Currently, surgery plus adjuvant chemotherapy are the mainstay of care in the treatment of ovarian cancer. Although this therapeutic strategy has been considered as "golden standard" regimen with profound impact on survival improvement, several obstacles have been encountered, such as chemotherapy drug resistance and disease relapse. Residual cancer cells in the abdominal cavity and vessels are considered as the main cause of disease relapse. New treatment options attempt to yield higher survival rate in patients. Monoclonal antibodies such as Trastuzumab and Cetuximab showed promising effects on several solid tumors. But for epithelial ovarian cancer, modalities of intravenous monoclonal antibody monotherapy have not achieved expected results as they have in the treatments of breast and colorectal cancer. Relatively low expression of matched receptors on ovarian cancer cells, as well as the intravenous delivery with less efficacy of intra-abdominal antibody accumulation, may account for lack of efficacy of monoclonal antibody on ovarian cancer. So we hypothesize that polyvalent antibodies boosted from rabbit by inoculating human tumor cells could deplete ovarian cancer cells through intraperitoneal route. The mechanisms may include interrupting ligand-receptor binding and thus result in blockage of intracellular signaling pathways such as EGFR and HER2 signal transduction, and possibly may also involve antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity.