Taxane & cyclophosphamide vs anthracycline & taxane-based chemotherapy as adjuvant treatment for breast cancer: a pooled analysis of randomized controlled trials by the Hellenic Academy of Oncology

// Panagiotis Ntellas 1, 2 , Nikolaos Spathas 3 , Sofia Agelaki 4 , Elias Zintzaras 2 and Emmanouil Saloustros 5 1 Department of Medical Oncology, University Hospital of Ioannina, Ioannina, Greece 2 Department of Biostatistics and Clinical Bioinformatics, Faculty of Medicine, University of Thessaly, Larissa, Greece 3 2nd Department of Medical Oncology, University Hospital Attikon, Athens, Greece 4 Department of Medical Oncology, University General Hospital of Heraklion, Heraklion, Crete, Greece 5 Department of Oncology, University General Hospital of Larissa, Larissa, Greece Correspondence to: Emmanouil Saloustros, email: esaloustros@med.uth.gr Keywords: early breast cancer; adjuvant; anthracycline; taxane; non-Inferiority Received: November 12, 2018 Accepted: December 16, 2018 Published: February 05, 2019 ABSTRACT Background: Adjuvant chemotherapy has an indisputable value for early breast cancer patients. Anthracycline and taxane-based regimens (TaxAC) have not been proven superior to taxane & cyclophosphamide (TC), a less toxic combination. Our objective was to estimate the cumulative evidence for non-inferiority of TC against TaxAC, in the adjuvant setting of patients with HER2-negative, breast cancer. Results: Overall, 7,341 patients were included in this analysis. Superiority of TaxAC or non-inferiority of TC was not established either for the overall population (DFS HR, 1.11; 95% CI, 0.95–1.30; p = 0.18), or for the node-negative patients (HR, 1.05; 95% CI, 0.82–1.34; p = 0.71). A difference in DFS of 1.28% (TC DFS, 89.04%; 95% CI, 88%–90% & TaxAC DFS, 90.32%; 95% CI, 89%–91%) was found in favor of TaxAC. Lower risk of death was not established for either treatment regimen (OS-HR, 1.02; 95% CI, 0.82–1.25; p = 0.88). Overall, the toxicity profile favored TC. Conclusion: Although non-inferiority of TC was not proven, superiority of TaxAC is still questioned. The present analysis narrows the risk of recurrence between the treatment groups. Considering TC has a more favorable safety profile, the question as to which treatment regimen should be preferred under what circumstances, needs to be individualized according to patients’ characteristics and desires. Methods: Treatment efficacy data from The ABC trials, the Plan B trial and a trial by the Hellenic Oncology Research group (HORG) were pooled. Disease free survival (DFS) and overall survival (OS) were scrutinized. A HR of 1.18 for TC versus TaxAC was chosen to demonstrate inferiority.