High-dose busulfan, melphalan and thiotepa as consolidation for noninflammatory high-risk breast cancer

The purpose of this study was to evaluate the toxicity and efficacy of high-dose busulfan, melphalan and thiotepa (Bu/Mel/TT) in patients with high-risk non-inflammatory breast cancer defined as stage II disease ≥ 10 lymph nodes (n = 52) or stage III (n = 69), and prognostic factors for treatment outcome. One hundred and twenty-one patients (median age, 46 years) were treated with high-dose Bu (12 mg/kg), Mel (100 mg/m²) and TT (500 mg/m²) (HDC) followed by autologous stem cell infusion (ASCI). One hundred patients were initially treated with surgery followed by standard adjuvant chemotherapy prior to HDC/ASCI. Twenty-one patients with stage III disease had inoperable tumors at diagnosis and were treated with neoadjuvant chemotherapy and surgery before HDC/ASCI. Transplant-related mortality was 6%. The probabilities of event-free survival (EFS) at 3 and 5 years (median follow-up of 36 months) from transplant were, for all patients: 0.62-0.60; stage II: 0.71-0.67: stage III: 0.55-0.55 (for stage III adjuvant and neoadjuvant groups: 0.60-0.60 and 0.42-0.42, respectively). Multivariate analysis did not identify variables associated with poor outcome. The efficacy of Bu/Mel/TT is similar to other HDC regimens reported for patients with high-risk non-inflammatory breast cancer. Bu/Mel/TT has high activity in stage II disease and a moderate benefit in stage III operable tumors.