Five-year update of an expanded phase ii study of dose-dense and -intense doxorubicin, paclitaxel and cyclophosphamide (ATC) in high-risk breast cancer

Objectives: This study evaluated the safety and efficacy of dose-dense and -intense sequential doxorubicin (A), paclitaxel (T) and cyclophosphamide (C) as adjuvant therapy for breast cancer (BC) with ≥ 4 ipsilateral axillary lymph nodes. Methods: Patients were recruited after BC surgery if ≥ 4 axillary nodes were involved by metastatic cancer. Planned treatment was A 90 mg/m ² three times every 14 days (q14d x 3), T 250 mg/m ² q14d x 3 and C 3 g/m ² q14d x 3 combined with filgrastim support. Results: The study enrolled 85 eligible patients. The median number of lymph nodes involved was 9. Mean dose intensity was >94% of planned for each drug. Common grade 3 toxicities included nausea and/or vomiting (24%), mucositis (18%), neuropathy (16%), palmar-plantar erythrodysesthesia (12%), myalgia (6%) and arthralgia (6%). Grade 3/4 neutropenia occurred in 77 (91%) patients, and 32 (38%) patients had neutropenic fever. One patient developed acute leukemia. Sixty-nine (81%) patients are alive, and 59 (69%) patients are alive and free of distant disease at a median follow-up of 5 years. Conclusions: ATC is a feasible regimen for adjuvant therapy of high-risk BC, with a relatively low rate of relapse at the 5-year follow up.