The predictive value of Ki-67 before neoadjuvant chemotherapy for breast cancer: a systematic review and meta-analysis

Aim: To review the predictive values of Ki-67 before neoadjuvant chemotherapy (NAC) for breast cancer patients. Methods: PubMed and EMBASE were searched. Random-effect model meta-analysis was conducted using Revman software. Results: High Ki-67 was associated with more pathological complete responses (pCRs) events (odds ratio: 3.10; 95% CI: 2.52–3.81; 53 studies, 10,848 patients) regardless of HR+, HER2+ and triple-negative breast cancer types, the definitions of pCR and cut-off points for Ki-67. Ki-67 could predict pCR in those who received anthracyclines plus taxanes, and anthracyclines only, and those from Asia and Europe. Conclusion: High Ki-67 before NAC was a predictor for pCR in neoadjuvant setting for breast cancer patients.