Potential Interplay between TLR4 Polymorphisms and Tumor Progesterone Receptors in Breast Cancer Prognosis

Background and Objective The most prevalent cancer in women worldwide is breast cancer (BC). Research shows that chronic inflammation may be linked to an increased risk of cancer. According to the evidence, the Toll-like receptor (TLR) family plays a significant part in controlling inflammation, innate immunity, cell division, and survival. Among the TLR family, TLR4 is one of the most researched members. It has been noted that BC cells exhibit high mRNA and protein expression levels of TLR4. This implies that single nucleotide polymorphisms (SNPs) in TLR4 gene may have functional effects on the morphology of BC and patient survival. Nevertheless, research on the relationship between SNPs in the TLR4 gene and BC is scarce worldwide. This study aimed to assess the impact of SNPs in the TLR4 gene on the clinical and morphological features of BC as well as the overall survival of BC patients. Material and Method The study population included 170 females with histopathologically confirmed earlystage primary BC (age ranged from 30 to 74 years; median – 46 years). Clinical and tumor pathomorphological data (tumor size, involvement of lymph nodes, metastases, differentiation degree, status of estrogen and progesterone receptors, human epidermal growth factor receptor 2 status, disease progression, and death) were obtained by oncologists. The follow-up period ended on November 30, 2024. Genomic DNA extraction was performed from patients’ blood using a spin column-based isolation method. Genotyping of TLR4 rs7873784 and rs7860896 was conducted by using the TaqMan probe assays on the QuantStudio™ 3 Real-Time PCR System. The strength of potential associations between SNPs and BC features were estimated by crude odds ratio (ORs) and 95% confidence intervals (CIs). Survival curves were generated using the Kaplan-Meier analysis. All statistical tests were performed using IBM SPSS Statistics 30.0.0.0 software, and p<0.05 was considered statistically significant. The study was approved by Kaunas Regional Biomedical Research Ethical Committee (no. BE-2-10 and P1-BE-2-10/2014). Results The genotype frequencies of tagging SNPs were all in agreement with Hardy-Weinberg equilibrium (p>0.05). The genotype distribution of rs7873784 was 0.788 for GG, 0.194 for GC, and 0.018 for CC. For rs7860896 AA, AG and GG genotypes, the distribution was 0.841, 0.147 and 0.012, respectively. The study demonstrated that rs7873784 and rs7860896 were associated with the tumor’s status of progesterone receptors. Females having the rs7873784 GC genotype compared to GG were predisposed to lower rates of progesterone receptor-negative tumors (OR=0.395; 95% CI 0.166-0.938; p=0.035). Meanwhile, rs7860896 AG genotype compared to AA was significantly associated with increased chances of progesterone receptors-negative BC (OR=2.400; 95% CI 1.007-5.718; p=0.048). No additional significant relationships were observed between the SNPs and the studied BC features. Furthermore, the SNPs in TLR4 gene did not correlate with the overall survival of the patients. Conclusions and Recommendations Results suggest that heterozygous genotypes of TLR4 rs7873784 and rs7860896 are associated with early-stage primary BC status of progesterone receptors and may be advantageous genetic biomarkers to assess the prognosis of BC. In order to evaluate the validity of these associations, more extensive and functional research is required.