PARP inhibitor plus chemotherapy versus chemotherapy alone in patients with triple-negative breast cancer: a systematic review and meta-analysis based on randomized controlled trials

Chemotherapy is the standard treatment for triple-negative breast cancer (TNBC). Whether the addition of PARP inhibitors improves treatment efficacy remains controversial clinically. Thus, we performed a meta-analysis to compare the efficacy and safety of combination treatment (PC) and chemotherapy alone (CA).

Relevant studies were identified through searches of 7 databases. The primary endpoints were progression-free survival (PFS) and overall survival (OS).

We screened 317 studies and included seven RCTs involving 2091 patients in the final analysis. PC tended to have better efficacy than CA according to PFS (HR [hazard ratio]: 0.83 [0.75, 0.93], p = 0.001), OS (HR: 0.89 [0.76,1.03], p = 0.11) and overall response rate (ORR) (RR [risk ratio]: 1.19 [0.97,1.46], p = 0.10). However, grade 3–5 AEs (RR: 1.50 [0.87,2.61], p = 0.15) were observed in the PC group. In the PC arm, the 10 most-reported grade 3–5 AEs were neutropenia (62.8%), anemia (28.5%), thrombocytopenia (26.4%), lymphopenia (19.05%), leukopenia (16.9%), fatigue (5%), heart failure (4.76%), lung infection (4.76%), thromboembolic events (4.76%) and ventricular tachycardia (4.76%). Similar results for pathological complete response (pCR), total AEs, rate of complete response (CR), stable disease (SD) and progressive disease (PD), breast conservation rate (BCR), and drug discontinuation (DD) rate were found between the two groups.

For TNBC treatment, the combination of PARP inhibitors and chemotherapy appears to be superior to chemotherapy alone with better antitumor efficacy. However, its higher rate of AEs needs to be taken seriously. More high-quality RCTs are needed to confirm these results.