Background: To evaluate the efficacy, safety, and potential advantages of Poly (ADP-ribose) polymerase inhibitors (PARPi) in treating BRCA-mutated breast cancer, we performed a meta-analysis of published studies.
Materials and methods: Four randomized controlled trials (RCTs) were included in the meta-analysis. Data analysis was conducted in Review Manager 5.4.
Results: The progression-free survival (PFS) of the patients with triple-negative (hazard ratio [HR] 0.81; 95% confidence interval [CI] 0.74-0.88; P < 0.00001) or hormone receptor-positive (HR 0.83; 95% CI 0.77-0.91; P < 0.0001) BRCA-mutated breast cancer was significantly extended in the containing PARPi therapy arm versus the chemotherapy arm. PFS of the patients who did not receive platinum-based therapy (HR 0.78; 95% CI 0.70-0.86; P < 0.0001) was significantly extended in the PARPi monotherapy arm versus the chemotherapy arm. The objective response rate of patients treated by PARPi monotherapy (risk ratio [RR] 2.51; 95% CI 1.81-3.47; P < 0.00001) was significantly higher than that of patients treated by chemotherapy. The incidence of thrombocytopenia in patients received PARPi combined therapy was obviously increased compared with chemotherapy group (RR 1.36; 95% CI 1.07-1.72; P = 0.01). PARPi monotherapy markedly increased the incidence of anemia (RR 5.83; 95% CI 2.64-12.88; P < 0.0001) versus chemotherapy. However, the risk of neutropenia (RR 0.48; 95% CI 0.29-0.81; P = 0.006) was reduced in the PARPi monotherapy arm. There were no statistical differences in other adverse events among these three groups.
Conclusions: PARPi combined therapy and monotherapy improved PFS of patients with BRCA-mutated breast cancer compared with standard chemotherapy, which was unrelated to type of BRCA mutation and status of hormone receptor. PARPi therapy has slightly higher hematological toxicity and better overall safety and tolerance.
Prospero registration number: CRD42020204385.
Keywords: BRCA-mutated breast cancer; Poly (ADP-ribose) polymerase inhibitors combined therapy; Poly (ADP-ribose) polymerase inhibitors monotherapy; chemotherapy.