Surgery for early non-small cell lung cancer with preoperative erlotinib (SELECT): A correlative biomarker study.

Abstract

7516 Background: Erlotinib has demonstrated major activity in EGFR mutation positive NSCLC, but may also benefit those with wild-type tumours. We conducted a single-arm trial of pre-operative erlotinib in early stage NSCLC to assess radiologic and functional response as well as correlation with known and investigational biomarkers. Methods: Patients with clinical stage IA-IIB NSCLC received erlotinib 150 mg daily for 4 weeks followed by surgical resection. Tumor response was assessed using pre- and post-treatment CT and PET imaging. Pharmacodynamic changes were assessed through comparison of pre- and post-treatment tumour samples (including Sequenom MassARRAY analysis) and measurement of circulating markers/ligands for EGFR activation (TGF-α, amphiregulin, epiregulin, EGFR SNP, EGFR ECD). Secondary endpoints included pathological response, toxicity and progression-free survival. Results: Twenty-five patients were enrolled; 22 received erlotinib treatment with a median follow up of 4.4 years (range 2.2 to 6.4 years). Histology was predominantly adenocarcinoma (14) with smaller numbers of squamous carcinoma (7) and large cell carcinoma (1). PET response (25% SUV reduction) was observed in 2 patients (9%), both with confirmed squamous carcinoma histology. All patients met criteria for stable disease by RECIST and several experienced minor radiographic regression with histologic findings of fibrosis/necrosis, including 2 with squamous histology. The presence of an EGFR exon 19 deletion was detected in one adenocarcinoma case; the patient experienced a minor radiographic response to treatment. Genotyping, functional protein assays and ligand analysis are ongoing. Conclusions: Erlotinib appears to demonstrate some activity in patients with squamous histology. While EGFR mutations have been infrequently demonstrated in squamous NSCLC, the potential exists for other biomarkers predictive of benefit. Clinical trial information: NCT00462995.