A Prospective Evaluation of the Association between a Single Nucleotide Polymorphism rs3775291 in Toll-Like Receptor 3 and Breast Cancer Relapse

Background Toll-like receptors (TLRs) regulate the balance between the innate and adaptive immune responses. Missense single nucleotide polymorphisms (SNPs) in TLRs might be functional and thus influence the risks of chronic infection and cancer development. Here, we investigated the association of two missense SNPs, rs3775291 (c. 1234G>A) in the TLR3 gene and rs4833095 (c. 743T>C) in the TLR1 gene, with relapse-free survival (RFS) in a cohort of prospectively observed breast cancer patients. Methods In this prospective observational study, rs3775291 in TLR3 and rs4833095 in TLR1 were genotyped in 715 patients with primary breast cancer in a Chinese population. Results Univariate analysis revealed that the patients with the AA genotype of rs3775291 had a shorter RFS compared with those carrying the G allele in the recessive model (P<0.01), but this finding was not observed with the dominant model (P = 0.31). The results remained significant after adjusting for the clinical parameters in the recessive model (HR = 3.53, 95% confidence interval [CI]: 1.98-6.31, P<0.01). Further survival analysis indicated that this SNP was significant in the luminal-B, triple-negative breast cancer (TNBC), and human epidermal growth factor receptor 2-positive (HER2+) patients using the recessive model but that it was not significant in the luminal-A patients. The SNP rs4833095 showed a non-significant tendency toward an increased RFS rate in the patients with the TT genotype. Conclusion Our results suggest that the SNP rs3775291 in TLR3 may influence patient outcome. Further studies with larger sample sizes should be conducted to validate our findings.