Associations of polymorphisms in microRNAs with female breast cancer risk in Chinese population

Polymorphisms in microRNA (miRNA) have been discussed to be associated with breast cancer risk; however, the conclusions were always inconsistent in different ethnicities. This case–control study enrolled 450 breast cancer cases, and 450 health controls was carried out to investigate the association between six polymorphisms in miRNAs and breast cancer risk. Sequenom MassARRAY was used to detect the polymorphisms in miRNAs, and the immunohistochemistry assay was applied to detect the expression of estrogen receptor (ER) and progesterone receptor (PR) in cancer tissue. The data showed that the 3746444 GG was associated with increased breast cancer risk (adjusted odds ratio (OR) = 1.71, 95 % confidence interval (CI) = 1.16–2.52) and that rs2292832 CC (adjusted OR = 0.54, 95 % CI = 0.34–0.85) was associated with decreased breast cancer risk. In addition, menopausal status subgroup analysis revealed that rs3746444 GG (adjusted OR = 2.34, 95 % CI = 1.31–4.15) and GA/GG (adjusted OR = 1.60, 95 % CI = 1.08–2.37) genotypes were associated with increased breast cancer risk for the subgroup of women with premenopausal status, respectively. Moreover, rs2910164 GG (adjusted OR = 1.84, 95 % CI = 1.07–3.15) and CG/GG (adjusted OR = 1.47, 95 % CI = 1.01–2.15) genotypes were associated with increased breast cancer risk in the postmenopausal status subcohort, respectively. Furthermore, rs3746444 AG (adjusted OR = 1.61, 95 % CI = 1.06–2.45) and AG/GG (adjusted OR = 1.49, 95 % CI = 1.02–2.18) genotypes were observed to be associated with increased risk of lymph node involvement and breast cancer with negative PR expression, separately. In short, rs3746444 was associated with breast cancer risk, especially for women with premenopausal status, and rs2910164 CG and CG/GG genotypes were associated with breast cancer risk for the women with premenopausal status.