Comprehensive evaluation of the relationship between biomarker profiles and neoadjuvant chemotherapy outcomes for breast cancer patients

Abstract

Abstract Background The prediction of response to neoadjuvant chemotherapy (NAC) in breast cancer patients could enable the adjustment of treatment strategies, improving the clinical management and overall outcomes. However, the current available studies on the relationship between biomarkers and NAC outcomes were limited to only a few predominant biomarkers. More importantly, many studies have reported conflicting findings on this issue. Given its clinical importance, we aimed to evaluate the predictive value of a wide range of clinically available molecular biomarkers for breast cancer, including HER2, ER, PR, TOPO II, EGFR, Ki67, CK5/6, AR and p53. Methods We included 189 patients with invasive breast cancer who received NAC at our institute. Biomarker profiles were assessed in both core-needle biopsies before NAC and surgical specimens after NAC. First, we analyzed the relationship between these biomarkers and the NAC outcomes in two aspects: pCR (pathological complete response) rate and tumor size reduction. Chi-square and Mann-Whitney U test were used to compare the biomarker status change in pCR and non-pCR patients accordingly. Linear regression analysis was performed to evaluate the relationship between biomarker status and tumor shrinkage rate. Second, we compared the expression status of these biomarkers before and after NAC administration using either Chi-square or Wilcoxon signed-rank test.