EGFR expression and survival in patients given cetuximab and chernoradiation for stage III non-small cell lung cancer: A secondary analysis of RTOG 0324

• Type of Material: Article
• Authors: Ritsuko Komaki, University of Texas MD Anderson Cancer Center; Rebecca Paulus, RTOG Statistical Center; George R. Blumenschein, Jr., University of Texas MD Anderson Cancer Center; Walter J Curran, Emory University; Francisco Robert, University of Alabama; Juliette Thariat, University of Texas MD Anderson Cancer Center; Maria Werner-Wasik, Thomas Jefferson University; Hak Choy, University of Texas Southwestern; Fred R. Hirsch, University of Colorado; K. Kian Ang, University of Texas MD Anderson Cancer Center
• Language: English
• Date: 2014-07-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 Elsevier Ireland Ltd. All rights reserved.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.radonc.2014.06.012
• Title of Journal or Parent Work: Radiotherapy and Oncology
• ISSN: 0167-8140
• Volume: 112
• Issue: 1
• Start Page: 30
• End Page: 36
• Grant/Funding Information: Supported by grants RTOG U10 CA21661, CCOP U10 CA37422, Stat U10 CA32115, P01 CA06294, and P30 CA016672 from the National Cancer Institute.
• Keywords: PROTEIN EXPRESSION; Science & Technology; Oncology; 1ST-LINE TAXANE/CARBOPLATIN; PLUS CETUXIMAB; CARCINOMA; RANDOMIZED PHASE-II; INDUCTION CHEMOTHERAPY; GROWTH-FACTOR-RECEPTOR; ONCOLOGY-GROUP; Erbitux; Inoperable lung cancer; Radiology, Nuclear Medicine & Medical Imaging; RADIOTHERAPY; GENE COPY NUMBER; Life Sciences & Biomedicine; Cetuximab; RTOG 0324
• Research Categories: Health Sciences, Oncology

Abstract

Purpose: We investigated whether expression of epidermal growth factor receptor (EGFR) was associated with survival and disease control in this secondary analysis of a phase II trial of cetuximab + chemoradiation for stage III non-small cell lung cancer. Methods: Patients received cetuximab weekly before and during radiation (63 Gy/35 fractions/7 weeks) with weekly carboplatin + paclitaxel. We analyzed EGFR expression by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in pretreatment biopsy specimens and compared findings with overall and progression-free survival (OS, PFS) and time to progression (TTP). Results: Specimens for IHC and FISH were collected from 51 and 45 of 87 evaluable patients. Pretreatment characteristics did not differ for patients with (n = 51) or without (n = 36) EGFR IHC data, or with (n = 45) or without (n = 42) FISH data. However, patients without IHC data had worse OS (HR = 1.63, P = 0.05), worse PFS (HR = 1.88, P = 0.008), and worse TTP [HR = 1.99, P = 0.01] than those with IHC data. EGFR protein expression was not related to pretreatment characteristics or OS; FISH-positive disease was associated with better performance status but not with OS, PFS, or TTP. Conclusions: Surprisingly, outcomes differed not by EGFR expression but by the availability of samples for analysis, underscoring the importance of obtaining biopsy samples in such trials.