Clinical characteristics associated with efficacy and prognosis among patients treated with PD-1/PD-L1 inhibitors for early-stage triple-negative breast cancers: A meta-analysis

Objective: To assess the efficacy of PD-1/PD-L1 inhibitors combined with chemotherapy for early-stage triple-negative breast cancer (TNBC) patients with different clinical characteristics.

Methods: Randomized clinical trials for PD-1/PD-L1 inhibitors and chemotherapy combination were included. Pooled analysis of odds ratio (OR) for pathological complete response (pCR) and hazard ratio (HR) for event-free survival (EFS) was conducted overall and for predefined subgroups.

Results: The combination of immunotherapy and chemotherapy significantly improved pCR rate in early TNBC patients (OR, 1.77), and the incidence of events was significantly reduced by 37%. Lymph node metastasis was associated with more benefits on pCR (OR[N0], 1.29; OR[N+], 2.57; P = 0.01), while earlier T stage was related to more benefits on EFS (HR[T1-T2], 0.48; HR[T3-T4], 0.85; P = 0.05).

Conclusion: The addition of PD-1/PD-L1 inhibitors to chemotherapy offers improved pCR and EFS in early TNBC patients. T and N stages may have implications for the efficacy.