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

IMPORTANCE

Several randomized trials of neoadjuvant chemo-immunotherapy in early triple negative breast cancer (TNBC) have been recently reported, showing conflicting results.

METHODS

We 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 addition and pCR (SOR = 1.72, 95 %CI: 1.22-2.42). The benefit was significant in the PD-L1 positive subgroup (SOR = 1.65; 95 %CI: 1.06-2.57). pCR was also significantly increased in the high-risk subgroup (SOR = 2.39; 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.

CONCLUSIONS

The addition of PD1/PD-L1 blockade to NACT significantly improves pCR rates in TNBC patients, particularly in patients at high-risk of relapse.