Background: The purpose of this study was to evaluate the impact of a dose-dense primary chemotherapy on pathological response rate (pCR) in patients with locally advanced breast cancer (LABC) treated with combined modality therapy.
Patients and methods: Stage IIIA/IIIB patients received three courses of induction chemotherapy (ICT) with cyclophosphamide, epirubicin and 5-fluorouracil (CEF) followed by local therapy (total mastectomy or segmental mastectomy with axillary nodes dissection) and adjuvant chemotherapy (ACT) with three courses of CEF alternated with three courses of cyclophosphamide, methotrexate, 5-fluorouracil (CMF). Patients were randomized to receive ICT and ACT every 3 weeks (arm A, 'standard treatment') or every 2 weeks with granulocyte-macrophage colony-stimulating factor (GM-CSF) support (arm B, 'dose-dense treatment'). In both arms radiotherapy was administered after the end of chemotherapy (in selected cases) and patients with hormonal receptor-positive tumors received tamoxifen for 5 years.
Results: A total of 150 patients were randomized (77 arm A and 73 arm B) and demographics were well balanced between the two arms. Compliance to treatment was excellent: 95% and 93% of patients in arms A and B, respectively, completed the treatment program with no modification or delay. Median duration of treatment (ICT+local+ACT) was 183 days (range 0-265) in arm A and 139 days (0-226) in arm B. The average relative dose intensity (ARDI) of chemotherapy was 1.3 with a 30% increase in the dose intensity in arm B in comparison with arm A. No difference in clinical [62%; 95% confidence interval (CI) 49% to 73.2%] and pathological response rates to ICT was observed between the two arms. Median follow-up was 5 years (range 1-96 months); median disease-free survivals were 4.8 years in arm A and 4.5 years in arm B. Median overall survival was 7.8 years in standard therapy: this figure has not yet been reached in the dose-dense treatment.
Conclusions: In LABC a dose-dense regimen, while allowing a 30% increase in the dose intensity of chemotherapy, did not provide significant improvement in pathological response rates. However, accelerated chemotherapy reduced the duration of the combined-modality program (6.1 versus 4.6 months) with no additional toxicities.