BACKGROUND: Numerous studies have yielded inconclusive results regarding the relationship between tumor suppressor protein TP53 overexpression and/or TP53 gene mutations and the response to neoadjuvant chemotherapy in patients with breast cancer. The purpose of the current study was therefore to evaluate the relationship between TP53 status and response to chemotherapy in breast cancer. METHODS AND FINDINGS: A total of 26 previously published eligible studies including 3,476 cases were identified and included in this meta-analysis. TP53 status (over expression of TP53 protein and/or TP53 gene mutations) was associated with good response in breast cancer patients who received neoadjuvant chemotherapy (total objective response: risk ratio [RR]= 1.20, 95% confidence interval [CI]= 1.09-1.33, p