Immunotherapy addition to neoadjuvant chemotherapy for early triple negative breast cancer: a systematic review and meta-analysis of randomized clinical trials.

Abstract

IMPORTANCE\nSeveral randomized trials of neoadjuvant chemo-immunotherapy in early triple negative breast cancer (TNBC) have been recently reported, showing conflicting results.\n\n\nMETHODS\nWe systematically searched PubMed, Cochrane CENTRAL, Embase and key oncological meetings for trials of neoadjuvant chemo-immunotherapy in TNBC. The primary endpoint was pCR, with sub-analyses based on PD-L1 expression and risk of relapse RESULTS: Five randomized trials enrolling 1496 TNBC patients were included. We observed a statistically significant association between PD1/PD-L1 blockade and pCR (SOR\u2009=\u20091.72, 95%CI: 1.22-2.42). The benefit was significant in the PD-L1 positive subgroup (SOR\u2009=\u20091.65; 95%CI: 1.06-2.57). pCR was also significantly increased in the high-risk subgroup (SOR\u2009=\u20092.39; 95%CI: 1.09-5.22), when restricting to patients receiving an anthracycline-based NACT. We found no significant association between immunotherapy addition and toxicity, and no evidence of publication bias.\n\n\nCONCLUSIONS\nThe addition of PD1/PD-L1 blockade to NACT significantly improves pCR rates in TNBC patients, particularly in patients at high-risk of relapse.