Background: Although Polycystic Ovary syndrome is a common endocrine disorder among women of reproductive age; is unclear whether PCOS increases the risk of subsequent development of, Gynecologic cancers namely breast cancer. The present study is aimed  to compare the anti-tumoral ability of peripheral blood mononuclear cells of women with PCOS with that of healthy controls using the co-culture system between effector cells and target tumor cell lines.

Methods: PBMCs were isolated from 25 women with PCOS and 25 healthy controls. Breast tumor cell lines were incubated as the two target cells and were cultured adjacent to PBMCs in the transwell co-culture system. Proliferation rate of the effectors cells evaluated by BrdU cell proliferation assay after 48 and 72 hours and T CD3⁺CD8⁺ lymphocytes were assessed using flow cytometry. Tumor necrosis factor alpha production was evaluated in cell culture supernatant by sandwich ELISA technique.

Results: After 48 hours incubation with tumor cell lines, the mean  proliferation score of PBMCs was significantly higher in PCOS group compared to that of  healthy controls (921.04 vs 287.6; P=0.002). In PCOS women, after 72 hours of incubation, TNF-α concentration was significantly reduced compared to 48-hour cultures (921.04±271.4 pg/dl vs 545.6±151.1 pg/dl at 48 h and 72 h intervals, P<0.05); it was increased in healthy controls.

Conclusion: The ability of PBMCs to produce TNF-α decreased gradually in PCOS group; as a result of which they may lack the ability required to form an in vitro efficient antitumor response to breast tumor cell lines.