Objective Programmed death-1 (PD-1), an important immunosuppressive molecule, plays a key role in tumor-cell-mediated immune escape. In the present study, we evaluated the effect of PD-1 gene polymorphisms on the risk of developing epithelial ovarian cancer (EOC) and patients' outcomes. Methods A case–control study was performed in 620 EOC patients and 620 control women. Survival data were available for 258 patients who received platinum-based chemotherapy after cytoreductive surgery. Results There were significant differences in the genotype and allele distribution frequencies of the PD-1.1 A/G between cases and controls (P=0.028 and P=0.02, respectively). Compared with the AA genotype, AG and GG genotypes may significantly decrease the risk of developing EOC (OR=0.71, 95%CI=0.54–0.94; OR=0.68, 95%CI=0.50–0.94, respectively). We did not find a significant difference in the genotype distribution frequency of the PD-1.5 C/T between cases and controls (P=0.096), but the frequency of T alleles was significantly lower in the EOC cases than that in the controls (P=0.033). Compared to the carriers with C alleles, the carriers with T alleles were at a significantly decreased risk of developing EOC (OR=0.82, 95%CI=0.69–0.98). Survival analysis showed that the two polymorphisms were not associated with patients' outcomes. Conclusions PD-1 gene polymorphisms may be involved in the development of EOC, but not associated with its clinical outcome in EOC patients among northern Chinese women.
