Relationships between EGFR Mutation Status of Lung Cancer and Preoperative Factors - Are they Predictive?

Katsuo Usuda,Hisao Tonami,Motoyasu Sagawa,Masakatsu Ueno,Tsutomu Sakuma,Mitsuru Taniguchi,Yoshimichi Ueda,Nozomu Motono,Yuichiro Machida,Munetaka Matoba,Makoto Tanaka

doi:10.7314/apjcp.2014.15.2.657

Katsuo Usuda, Hisao Tonami + Show 9 more

Open Access

https://doi.org/10.7314/apjcp.2014.15.2.657

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Abstract

The epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it means that EGFR-tyrosine kinase inhibitor treatment is indicated. The purpose of this prospective study is to determine whether EGFR mutation status could be identified with reference to preoperative factors. One hundred-forty eight patients with lung cancer (111 adenocarcinomas, 25 squamous cell carcinomas and 12 other cell types) were enrolled in this study. The EGFR mutation status of each lung cancer was analyzed postoperatively. There were 58 patients with mutant EGFR lung cancers (mutant LC) and 90 patients with wild-type EGFR lung cancers (wild-type LC). There were significant differences in gender, smoking status, maximum tumor diameter in chest CT, type of tumor shadow, clinical stage between mutant LC and wild-type LC. EGFR mutations were detected only in adenocarcinomas. Maximum standardized uptake value (SUVmax:3.66±4.53) in positron emission tomography-computed tomography of mutant LC was significantly lower than that (8.26±6.11) of wild-type LC (p<0.0001). Concerning type of tumor shadow, the percentage of mutant LC was 85.7% (6/7) in lung cancers with pure ground glass opacity (GGO), 65.3%(32/49) in lung cancers with mixed GGO and 21.7%(20/92) in lung cancers with solid shadow (p<0.0001). For the results of discriminant analysis, type of tumor shadow (p=0.00036) was most significantly associated with mutant EGFR. Tumor histology (p=0.0028), smoking status (p=0.0051) and maximum diameter of tumor shadow in chest CT (p=0.047) were also significantly associated with mutant EGFR. The accuracy for evaluating EGFR mutation status by discriminant analysis was 77.0% (114/148). Mutant EGFR is significantly associated with lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chest CT. Preoperatively, EGFR mutation status can be identified correctly in about 77 % of lung cancers.

Highlights

Epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it indicates induction of epidermal growth factor receptor (EGFR)-TKI treatment
EGFR mutation has been reported to be strongly related with never-smoker, female, adenocarcinoma and Asians, more detailed factors are needed to help identify EGFR mutation
Female, never-smoker, smaller maximum tumor diameter in chest CT, ground glass opacity (GGO) lesion, smaller SUVmax, earlier clinical stage, and adenocarcinoma were found to be related to EGFR mutation

Summary

Introduction

Epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it indicates induction of EGFR-TKI (tyrosine kinase inhibitor) treatment. Diffusion of water molecules in malignant tumors is usually restricted compared to that in normal tissue, resulting in a decreased apparent diffusion coefficient (ADC) value (Nasu et al, 2004) It is uncertain whether an examination of PET-CT or DWI is useful for the identification of EGFR mutation status. The epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it means that EGFR-tyrosine kinase inhibitor treatment is indicated. Conclusions: Mutant EGFR is significantly associated with lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chest CT. EGFR mutation status can be identified correctly in about 77 % of lung cancers

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