The association of epidermal growth factor receptor (EGFR) mutation and survival in N2(+) non-small cell lung cancer patients treated with platinum-based neoadjuvant concurrent chemoradiotherapy.

Abstract

7034 Background: Epidermal growth factor receptor (EGFR) mutation is reported to be associated with radiosensitivity of non-small cell lung cancer (NSCLC) in vitro. The aim of this study is to analyze the association of clinical outcome to neoadjuvant concurrent chemoradiotherapy (CCRT) with EGFR mutation status in N2(+) NSCLC patients. Methods: We retrospectively identified 161 patients with mediastinoscopy-proven N2(+) NSCLC who were treated with platinum-based neoadjuvant concurrent chemoradiotherapy at Samsung Medical Center between 1998 and 2006. In 98 patients with remaining tumor tissue, EGFR mutation was assessed by both peptide nucleic acid (PNA)-mediated PCR clamping method and sequencing simultaneously. 88 patients were finally included in analysis, excluding 4 patients with indeterminate EGFR mutation results and 6 patients who didn’t proceed to operation by reason of other than disease progression. Results: Among 88 patients, EGFR mutation (exon 19 deletions or L858R) was detected in 13 patients (14.8%), and KRAS mutation in 2 patients (2.3%). After neoadjuvant concurrent chemotherapy, 5 patients showed progressive disease, pathologic downstaging of lymph nodes (LN) to N0 or N1 was achieved in 44 patients (50%), and pathologic CR in 13 patients (14.8%). Achievement of pathologic CR or pathologic downstaging of LNs were not associated with EGFR mutation status. With a median follow-up of 73.8 months, there were no significant difference in overall survival or progession free survival between EGFR mutation and negative patients (28.2 months vs 33.6 months, p=0.125; 15.2 months vs. 18.0 months, p=0.631), respectively. Conclusions: In N2-positive NSCLC patient, EGFR mutation didn’t show any significant clinical benefit to neoadjuvant CCRT in terms of response rate, PFS or OS. Further study should be needed to confirm and elucidate the association between EGFR mutation status and radiosensitivity in NSCLC patients.