The impact of clinical outcomes according to EGFR mutation status in patients with locally advanced lung adenocarcinoma who recieved concurrent chemoradiotherapy.

OBJECTIVES: Among patients with locally advanced lung adenocarcinoma, the frequency of epidermal growth factor receptor (EGFR) and KRAS mutations was unknown. In addition, it has not been fully evaluated about the role of these mutations treated with concurrent chemoradiotherapy (CCR).

METHODS: The clinical records of locally advanced lung adenocarcinoma patients treated with CCR at Shizuoka Cancer Center between September 2002 and December 2009 were reviewed.

RESULTS: Forty-four patients were eligible for this study. EGFR mutation was detected in 13 (29.5%) of 44 patients, and KRAS mutation was detected in 2 (6.5%) of 31 patients. Among EGFR mutation status known patients, overall response rate, median progression-free survival (PFS), and median survival time were 52.3%, 11.5 months, and 35.8 months, respectively. Overall response rate was significantly higher in EGFR mutant group than in EGFR wild-type group (76.9% vs. 41.9%, P=0.02), but this difference did not translate into a significant PFS benefit (9.6 vs. 13.2 mo, P=0.78). Locoregional relapse occured less frequently in patients with EGFR mutation than those with EGFR wild-type, but not significant (15.4% vs. 32.3%, P=0.46). Brain was the most frequent metastatic site of relapse in EGFR mutant group.

CONCLUSIONS: Among locally advanced lung adenocarcinoma, EGFR mutation was detected in 29.5% and KRAS mutation was detected in 6.5%. We were not able to detect a difference in PFS or overall survival between EGFR mutant and wild-type patients treated with conventional CCR. Locoregional relapse was approximately half in the EGFR mutant group compared with the EGFR wild-type group; however, this finding did not reach statistical significance.