Conference Proceedings

Expanded RAS and BRAF V600 testing as predictive biomarkers for single agent cetuximab in the randomized phase III CO.17 trial.

Jonathan M Loree, Anthony Dowers, Dongsheng Tu, Christopher J O'Callaghan, Dan Edelstein, Hannah Quinn, Derek J Jonker, Chris Karapetis, Timothy Jay Price, John Raymond Zalcberg, Malcolm J Moore, Paul Michael Waring, Hagen F Kennecke, Stanley R Hamilton, Scott Kopetz

JOURNAL OF CLINICAL ONCOLOGY | AMER SOC CLINICAL ONCOLOGY | Published : 2019

Abstract

537 Background: KRAS/NRAS ( RAS) testing of exons 2, 3 and 4 is standard prior to anti-EGFR treatment in metastatic colorectal cancer and many consider BRAFV600 ( BRAF) mutations predictive. CO.17 was a randomized phase III trial comparing cetuximab vs best supportive care (BSC) in unselected patients (pts). Re-analysis tested only KRAS exon 2, thus the benefit of cetuximab in RAS/BRAF wild type (WT) pts is unclear. Methods: We retrospectively performed expanded RAS/BRAF testing using a highly sensitive digital PCR method (BEAMing; 1% allele frequency detection limit) on micro-dissected archival tissue from 248 CO.17 pts. Additional pts without available archival tissue, with prior Sanger s..

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