Dose-tailoring of FEC adjuvant chemotherapy based on leukopenia is feasible and well tolerated. Toxicity and dose intensity in the Scandinavian Breast Group phase 3 adjuvant Trial SBG 2000-1

Abstract

The SBG 2000-1 trial is a randomised study that investigates if dose-tailored adjuvant FEC therapy based on the individual's leukocyte nadir value can improve outcome. The study has included 1535 women with medium and high-risk breast cancer. Patients and methods. After a first standard dosed FEC course (5-fluorouracil 600 mg/m², epirubicin 60 mg/mg² and cyclophosphamide 600 mg/m²), patients who did not reach leukopenia grade III or IV were randomised to standard doses (group standard) or doses tailored to achieve grade III leukopenia (group tailored) at courses 2–7. Patients who achieved leukopenia grade III or more after the first course were not randomised but continued on standard doses (group registered). Results. Both planned and actually delivered number of courses (seven) were the same in all three arms. The relative dose intensity was increased by a factor of 1.31 (E 1.22, C 1.43) for patients in the tailored arm compared to the expected on standard dose. Ninety percent of the patients in the tailored arm achieved leukopenia grade III–IV compared with 29% among patients randomised to standard dosed therapy. Dose tailoring was associated with acceptable acute non-haematological toxicity with more total alopecia, nausea, vomiting and fatigue. Conclusion. Dose tailoring according to leukopenia was feasible. It led to an increased dose intensity and was associated with acceptable excess of acute non-haematological toxicity.