Meta-analysis confirms achieving pathological complete response after neoadjuvant chemotherapy predicts favourable prognosis for breast cancer patients.

Neoadjuvant chemotherapy (NAC) has become a widely accepted method of sequencing systemic therapy for breast cancer treatment. While 'response to chemotherapy' in the neoadjuvant setting has been utilised to predict prognosis, the published data are inconsistent. The present meta-analysis was conducted to determine whether the pathologic response to NAC predicts for outcomes. Papers were selected from the PubMed database based on defined inclusion and exclusion criteria. Parameters such as number/percentage of patients having pCR and outcome statistics (i.e. overall survival (OS), disease-free survival (DFS), relapse-free survival (RFS)) were collected. The analysis included 16 studies with 3776 patients. The summary odds ratio (OR) estimating the association of OS with pCR was 3.44 (95% confidence interval [95%CI]: 2.45-4.84), with similar findings for DFS (OR=3.41, 95%CI: 2.54-4.58) and RFS (OR=2.45, 95%CI: 1.59-3.80). No obvious statistical heterogeneity was detected. Funnel plots and Egger's tests did not reveal publication bias. This meta-analysis confirms that pathologic response is a prognostic indicator for RFS, DFS and OS and suggests that patients achieving pCR after NAC have favourable outcomes.