Prognostic value of receptor status conversion following neoadjuvant chemotherapy in breast cancer patients: a systematic review and meta-analysis.

Biomarkers of breast cancer such as hormone receptors (HR) and human epidermal growth factor 2 (HER2) can be altered after neoadjuvant chemotherapy (NAC). However, whether the conversion of these receptors affects the prognosis of patients remains to be determined. We sought to evaluate the prognostic value of HR and HER2 receptors before and after NAC and to analyze their clinical implications. Relevant studies were used to calculate the pooled hazard ratios, 95% confidence interval (95% CI). This meta-analysis included eight studies with 2847 patients. Compared to patients with HR+ → +, patients with HR+ → - have shorter disease free survival (DFS) (hazard ratio = 2.64, 95% CI 1.86-3.75) and overall survival (OS) (hazard ratio = 2.99, 95% CI 1.97-4.54). Furthermore, patients with HR- → + tend to achieve better DFS (hazard ratio = 0.83, 95% CI 0.60-1.17) compared to patients with HR- → -. Patients with HR- → + gain better OS (hazard ratio = 0.67, 95% CI 0.46-0.99) compared to patients exhibiting HR- → -. When comparing patients with HER2+ → - to patients with HER2+ → +, patients with HER2+ → - tended to achieve better DFS (hazard ratio = 1.65, 95% CI 1.08-2.53) though results for OS (hazard ratio = 1.16, 95% CI 0.54-2.49) were not statistically significant. Our data strongly support the need for redetection of HR and HER2 receptor status of surgical sample following neoadjuvant therapy. Changes in HR status induced by NAC can be used as a prognostic factor in breast cancer patients for predicting both OS and DFS. HER2 change may also be valuable for predicting prognosis. Further research should explore therapeutic strategies for those presenting receptor status conversion.