High p95HER2/HER2 Ratio Associated With Poor Outcome in Trastuzumab-Treated HER2-Positive Metastatic Breast Cancer NCCTG N0337 and NCCTG 98-32-52 (Alliance).

ABSTRACT: Purpose: p95HER2 is a truncated form of HER2 that confers resistance to trastuzumab in vitro, but clinical results have been conflicting to date. Given that p95HER2 levels correlate with total HER2 expression levels, which confer better outcomes, we sought to evaluate the p95HER2/HER2 ratio in the North Central Cancer Treatment Group N0337 and N98-32-52 trials.Experimental Design: The HERmark assay and VeraTag technology (Monogram Biosciences) were used to measure total HER2 and p95HER2 expression levels in 91 patient samples.Results: In the multivariate model, increasing total HER2 level was significantly associated with longer (OS; HR, 0.33; P = 0.002) and decreasing p95HER2 level was significantly associated with longer OS (HR, 4.2; P = 0.01). Total HER2 expression level was significant

SUBMITTER: Chumsri S 

PROVIDER: S-EPMC6314664 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature