The transcription factor KLF4 as an independent predictive marker for pathologic complete remission in breast cancer neoadjuvant chemotherapy: a case-control study

Background: To identify whether a stem cell biomarker, KLF4, may predict the pathologic tumor response to neoadjuvant chemotherapy for patients with locally advanced breast cancer. Methods: Twelve locally advanced breast cancer patients who achieved pathologic complete remission (pCR) after neoadjuvant chemotherapy were identified and for each, three non-pCR breast cancer patients - matched for age, clinical tumor-node-metastasis stage, and neoadjuvant chemotherapy cycles - were selected. The relationship between KLF4 expression in the core needle biopsied cancer tissue and patient pCR rate was assessed using univariate and multivariate analysis. Results: Receiver operating characteristic curve analysis showed that the patients with a histoscore of KLF4 expression >0.18 had a lower pCR rate. Multivariable analysis showed that higher KLF4 expression (odds ratio 0.013; 95% confidence interval 0.013-0.444; P=0.004) was independently correlated with a lower pCR rate after neoadjuvant chemotherapy. Conclusion: KLF4 overexpression was associated with lower pCR in locally advanced breast cancer patients undergoing neoadjuvant chemotherapy. This study suggests that KLF4 may serve as a predictor for pCR in patients with breast cancer after neoadjuvant chemotherapy.