Association between different potential predictive markers from TRUST, a trial of erlotinib in non-small cell lung cancer (NSCLC)

7651 Background: Recent studies have examined potential predictive markers in NSCLC patients (pts) treated with EGFR tyrosine kinase inhibitors. However, few data are available on inter-relationships between different markers. Clinical and molecular markers were analyzed for patients from TRUST, an open label, non-randomized trial initiated to provide erlotinib access to pts with advanced NSCLC. Methods: 393 German pts (99% Caucasian) with stage IIIb/IV NSCLC were included. Markers/characteristics assessed were: EGFR (282 pts) and phosphorylated MAPK (pMAPK; 109 pts) using immunohistochemistry (IHC; positive status was defined as: ≥10% of tumor cells with any membrane staining for EGFR; and H-score ≥200 for pMAPK), EGFR gene copy number (135 pts) using fluorescence in-situ hybridization (FISH), EGFR mutations (86 pts), KRAS mutations (108 pts), tumor type (281 pts), smoking status (392 pts) and gender (393 pts). Results: EGFR FISH+ pts were likely to also be EGFR IHC+: 92.9% (26/28) of EGFR FISH+ pts were...