Platinum dose in neoadjuvant therapy for triple-negative breast cancer: A systematic review and network meta-analysis

There are multiple neoadjuvant regimens, including platinum agents for triple-negative breast cancer (TNBC), each with a different safety profile, outcome, and pathologic complete response rate (pCR%). We performed a systematic review and network meta-analysis to compare the efficacy and safety of different platinum-based neoadjuvant CT treatments for TNBC. Bibliographic databases (PubMed, Embase, and Cochrane Library) were searched from their inception to October 31, 2022. Eligible studies were randomized clinical trials that evaluated the addition of carboplatin or cisplatin to standard neoadjuvant CT for TNBC. The primary endpoints were pCR rates and DFS/EFS, while the secondary endpoints were grade (G)3-4 hematological toxicity and OS. Thirteen trials involving 3154 patients comparing six treatments (carboplatin AUC 5, carboplatin AUC 6, carboplatin AUC 2, carboplatin AUC 1.5, cisplatin 75 mg/m2, and standard anthracycline-and/or taxane-based CT) were identified. Based on the most effective treatments added to neoadjuvant CT, carboplatin AUC 2 was associated with the least improvement in pCR% (RR, 1.49; 95%CI, 1.23, 1.8), carboplatin AUC 6 was associated with similar improvement in pCR% (RR 1.58, 95%CI, 1.35, 1.84) and carboplatin AUC 5 with the highest improvement in pCR% (RR 2.23, 95%CI, 1.6,32). The treatment associated with the most considerable improvement in DFS when added to neoadjuvant CT was carboplatin AUC 5 (HR 0.36, 95%CI 0.18, 0.73). It was also better than AUC 6 and AUC 2 (HR= 0.45, 95%CI 0.21-0.96 and HR=0.48, 95%CI 0.23-0.98). All schedules exhibited similar outcomes in terms of OS; however, only AUC 2 demonstrated a significant improvement compared to the no-platinum arms. Neutropenia, thrombocytopenia, and anemia G3-4 were significantly increased by carboplatin AUC 6. Based on this network meta-analysis, carboplatin AUC 5 added to standard neoadjuvant CT may provide substantial pCR and DFS benefits with a low toxicity risk compared to other carboplatin doses.