Purpose: Although dose-dense (dd) chemotherapy plays a fundamental role in the treatment of breast cancer (BC), a variety of trials have presented divergent survival results. Here, we present data of patients with more than 3 positive axillary lymph nodes (+aLN) receiving dd chemotherapy after a median follow-up period of 12.3 years.
Methods: In the years 1996-2000, 231 patients with invasive BC, ≥pN2a and no evidence of distant metastases were recruited to receive treatment A, i.e. dd 3 × epirubicin (E, 90 mg/m2) + paclitaxel (P, 175 mg/m2) every 2 weeks (q2w) followed by 3 × cyclophosphamide (C)/methotrexate/5-fluorouracil (CMF, 600/40/600 mg/m2, q2w), or treatment B, i.e. 4 × E + C (C, 600 mg/m2) q3w followed by 3 × CMF q3w.
Results: 113 patients in arm A and 113 patients in arm B were analysed after an updated median follow-up of 12.3 years. The median age was 55 years, with a median number of 6 +aLN, 50.4% had a T2 and 79.2% hormone receptor-positive BC. The disease-free survival (DFS) rate was 53.1% in arm A and 42.5% in arm B (adjusted p = 0.027). The overall survival (OS) rate was 54.9% in arm A and 48.7% in arm B (adjusted p = 0.058). In the multivariable analysis, the tumour burden was a significant predictor for DFS and OS.
Conclusion: The adjuvant use of dd chemotherapy led to a statistically significant improvement of DFS after a follow-up of 12.3 years.
Keywords: Adjuvant dose-dense chemotherapy; Disease-free survival; Long-term follow-up; Node-positive early breast cancer; Overall survival.