Abstract P2-09-08: c-MYC (MYC) Protein Expression and Associations with Trastuzumab Benefit in Early-Stage, HER2+ Breast Cancer in Context of the NCCTG Adjuvant Trial, N9831

Previous findings suggested that patients (pts) with copy number alterations of MYC (8q24) and centromere 8 (CEN 8) in the setting of HER2-positive breast cancer may be associated with improved outcome to adjuvant trastuzumab. Our tissue microarray (TMA) data suggested that alternate cutpoints for MYC copy number anomalies [of 802 pts, those with MYC:CEN8 ratio ≥1.3 or 30% a priori. Median follow-up was 5.8 years. Results: Of 1220 pts with completed IHC analyses, 557 (46%) were MYC+. MYC+ was associated with a higher rate of hormone receptor positivity (58% vs 48%, chi-sq P Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-08.