PANTHER: Prospective randomized phase III trial of tailored and dose-dense versus standard tri-weekly adjuvant chemotherapy for high-risk breast cancer in the modern era of endocrine and anti-HER2 therapy.

Abstract

1002Background: Standard dosing of chemotherapy (ct) based on body surface area results in marked inter-patient variation in pharmacokinetics, toxicities and efficacy. Methods: 2,017 patients with node-positive or high-risk node-negative breast cancer were randomized (1:1) in 86 centers in Sweden, Austria and Germany between February 2007 and September 2011 to either four cycles of leukocyte nadir-based tailored and dose-dense adjuvant epirubicin (E) 38-120 mg/m 2, start at 90 mg/m 2) and cyclophosphamide (C) 450-1200 mg/m 2, start at 600 mg/m 2) Q2W, followed by four cycles of docetaxel (D) 75-100 mg/m 2, start at 75 mg/m 2) Q2W (three weeks pause between EC and D) (tdd arm) or three cycles of standard 5-Fluorouracil (F) 500 E100 C500 Q3W followed by three cycles of D100 Q3W (control arm). Total treatment duration was the same in the two arms. The primary endpoint was breast cancer relapse-free survival (BCRFS) assessed in the intention to treat population. Secondary endpoints included event-free surviva...