PD-1 rs2227982 polymorphism is associated with the decreased risk of breast cancer in northwest Chinese women

Programmed death-1 (PD-1) is crucial in cancer and is well characterized as a negative T-cell regulator that functions by delivering inhibitory signals. We aimed to evaluate the relationship between PD-1 polymorphisms (rs10204525, rs2227982, and rs7421861) and breast cancer risk. We selected 560 breast cancer patients and 583 age-, sex-, and ethnicity-matched healthy controls from Northwest China. The PD-1 polymorphisms were genotyped by using Sequenom MassARRAY. Associations were estimated with odds ratios (ORs) and 95% confidence intervals (95% CIs). For the rs10204525 and rs7421861 polymorphisms, no differences in breast cancer risk were found in any of the genetic models. For the rs2227982 polymorphism, the variant genotypes were significantly associated with decreased breast cancer risk (CT vs CC: OR = 0.68, 95% CI = 0.52-0.91; CT + TT vs CC: OR=0.69, 95% CI=0.53-0.90). In analyses stratified by age, the decreased risk was observed among the younger subjects (OR=0.68, 95% CI=0.47-0.97). We found that the decreased risk observed for the variant genotypes of rs2227982 was associated with the Her-2 status (CT vs CC: OR=0.55, 95% CI=0.37-0.84; CT + TT vs CC: OR=0.56, 95% CI=0.38-0.82). The haplotype analysis showed that the A rs10204525 T rs2227982 C rs7421861 haplotype was associated with a significantly decreased risk of breast cancer (OR=0.50, 95% CI=0.34-0.75). Our findings support an association between the PD-1 rs2227982 polymorphism and decreased breast cancer risk, especially in Her-2 positive breast cancer patients in the Chinese population.