Background: Germline genetic polymorphisms in certain genes are associated with the response to anthracycline- and taxane-based neoadjuvant chemotherapy in breast cancer (BC). This translational study aims to evaluate the potential role of rs1042713 in the beta 2-adrenergic receptor (ADRB2 ) gene in predicting pathological complete responses (pCRs) to taxane- and platinum-based neoadjuvant chemotherapy in locally advanced breast cancer (LABC).
Materials and methods: The distribution frequencies of rs1042713 were genotyped in LABC patients who received taxane- and platinum-based neoadjuvant chemotherapy. Associations between tumor-relevant biomarkers, genotypes and pCRs were evaluated using Student’s t-test for continuous variables and Chi-square or Fisher’s exact test for categorical variables. For univariate analysis, the relationship between the rs1042713 polymorphism and pCR was analyzed by Chi-square or Fisher’s exact test. The modified ORs with their 95% CIs were calculated by a multivariate logistic regression analysis to explore the association between genotype and pCR.
Results: There was a significant correlation of the rs1042713 genotype with estrogen receptor (ER) status (P=0.008). Significant differences were detected in the rs1042713 genotypes of pCR and non-pCR patients (P =0.046). The pCR rate was 18.2% in patients with ADRB2  rs1042713 AA genotypes and 38.7% in AG+GG genotypes. Women carrying the AG+GG (OR=2.91, 95% CI: 1.02–8.29, P =0.046) genotype had a higher pCR rate than those with the AA genotype.
Conclusion: rs1042713, which is located in the ADRB2  gene, could predict pCR to taxane- and platinum-based neoadjuvant chemotherapy in LABC. This finding suggests that rs1042713 could play a potential role as a predictive marker in clinical settings.
Keywords: beta 2-adrenergic receptor gene, locally advanced breast cancer, neoadjuvant chemotherapy, pathological complete response, polymorphism