Efficacy and safety of cyclophosphamide in anthracycline- and taxane-based neoadjuvant chemotherapy in breast cancer: a meta-analysis.

backgroundOur study aimed to compare the efficacy and safety of anthracycline plus taxane (AT)-based neoadjuvant chemotherapy (NAC) with or without cyclophosphamide in the treatment of breast cancer.

methodsWe searched PubMed, Embase, Web of Science and the Cochrane Library for randomized controlled studies comparing the efficacy and safety of AT-based NAC with or without cyclophosphamide in breast cancer patients.

resultsFour eligible studies with 2,302 individuals were ultimately included in the quantitative analysis. After applying the AT-based NAC regimen, the overall rates of pathologic complete response (pCR) and breast conserving surgery in all included subjects were 26.5% and 70.6%, respectively. The rates of pCR [risk ratio (RR): 1.35; 95% CI: 0.75, 2.45; P=0.32], breast-conserving surgery (RR: 1.07; 95% CI: 0.97, 1.19; P=0.17) and clinical response (RR: 1.08; 95% CI: 0.97, 1.19; P=0.15) in patients in the cyclophosphamide group were similar to those in the control group. However, participants in the cyclophosphamide group had a lower no clinical response rate than those in the control group (RR: 0.72; 95% CI: 0.60, 0.87; P<0.001). Subjects in the cyclophosphamide group had significantly lower rates of infection (RR: 0.57; 95% CI: 0.41, 0.79; P<0.001) and diarrhea (RR: 0.46; 95% CI: 0.30, 0.68; P<0.001) and higher rates of thrombocytopenia (RR: 3.38; 95% CI: 1.96, 5.84; P<0.001), sensory/motor neuropathy (RR: 1.57; 95% CI: 1.03, 2.39; P=0.03) and nausea/vomiting (RR: 1.51; 95% CI: 1.11, 2.06; P=0.009) than those in the control group.

conclusionsThe AT-based NAC regimen with or without cyclophosphamide had similar clinical outcomes in breast cancer patients. The addition of cyclophosphamide might increase the risks of thrombocytopenia, sensory/motor neuropathy and nausea/vomiting.