This study aimed to assess the associations of two common Flap endonuclease 1 (FEN1) polymorphisms (rs4246215 and rs174538) with breast cancer risk in northwest Chinese women. We conducted a case-control study with 560 breast cancer patients and 583 age-matched healthy controls from Northwest China. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to estimate the associations. We found a significantly reduced risk of breast cancer associated with T allele of rs4246215 (allele model: OR 0.81, 95% CI 0.68-0.96; homozygote model: OR = 0.59, 95% CI = 0.40-0.87; recessive model: OR = 0.61, 95% CI = 0.42-0.89), especially in postmenopausal women (OR = 0.58, 95% CI = 0.35-0.97). Furthermore, the polymorphism showed a decreased association with larger tumor size (heterozygote model: OR = 0.63, 95% CI = 0.44-0.92; dominant model: OR = 0.63, 95% CI = 0.44-0.90). For rs174538, we did not find any difference in all genetic models. However, rs174538 was associated with lymph node metastasis (heterozygote model: OR = 0.57, 95% CI = 0.39-0.81; dominant model: OR = 0.61, 95% CI = 0.43-0.86) and estrogen receptor status (heterozygote model: OR = 1.50, 95% CI = 1.05-2.15; dominant model: OR = 1.42, 95% CI = 1.01-1.98). Haplotype analysis showed that Trs4246215Grs174538 haplotype was a protective factor of breast cancer (OR = 0.34, 95% CI = 0.14-0.81). Our results suggest that FEN1 polymorphisms may reduce the risk of breast cancer in Chinese women.
Keywords: breast cancer; case-control study; flap endonuclease 1; risk.