Molecular marker assessments for epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) and histoscore (H-score) in the phase III SELECT trial.

8052 Background: SELECT was a phase III study that investigated whether the addition of cetuximab (C) to pemetrexed (P) improved outcome in previously treated patients (pts) with recurrent or progressive non-small cell lung cancer (NSCLC). Clinical results have been reported previously and demonstrated that adding C to P did not improve progression-free survival (PFS) or overall survival (OS). H-score has been reported to be a potential predictor of outcome for C therapy. Prespecified biomarker analyses, including EGFR IHC and H-score, are reported here. Methods: EGFRexpression in tumor tissue was not required for eligibility; however, tissue was collected and analyzed for EGFR expression by IHC using standard methods. In addition, H-score evaluation was performed by trained central pathologists and correlated with clinical outcome using a predefined cutoff for “low” and “high” of <200 and ≥200, respectively. Results: A total of 449 (IHC) and 406 (H-score) pt specimens were evaluable. Demographics for pts...