Adjuvant Lapatinib In Women With Early-Stage Her2-Positive Breast Cancer (Her2+Bc): Analysis Of The Hormone Receptor-Negative Subgroup Of The Intent-To-Treat (Itt) Population Of The Teach Trial.

596 Background: TEACH is a randomized, double-blind, placebo (P)-controlled trial evaluating lapatinib (L) in reducing relapse risk in trastuzumab -naive patients (pts) previously treated with chemotherapy for HER2+ BC. The primary results (presented at SABCS 2011) showed a hazard ratio (HR) for disease-free survival (DFS) in L arm compared with P of 0.83 (95% confidence interval [CI] 0.70-1.00; stratified log-rank 2-sided P=.053). The predefined hormone receptor negative subgroup was analyzed, which in contrast to the hormone receptor positive subgroup of the ITT population (N=3147) had a significantly improved DFS. Methods: 3161 HER2+ BC pts (Stage I-IIIc) were randomized 1:1 to L daily or P for 1 year (yr). Primary endpoint was DFS in the ITT population. Central nervous system (CNS) recurrence rate was a secondary endpoint. A subgroup analysis by Cox Proportional Hazards Regression Models was performed for the hormone receptor negative pts from the ITT population. Results: 1288 pts (41%) comprised the ...