The relationship between epidermal growth factor receptor mutation and histologic subtype of lung adenocarcinoma with stage I according to the new classification

Objective: To investigate the relationship between epidermal growth factor receptor (EGFR) mutation and histologic subtypes of lung adenocarcinoma and clinical characteristics according to the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society international multidisciplinary classification of lung adenocarcinoma. Methods: The mutation of EGFR gene in 100 specimens of stage Ⅰ lung adenocarcinoma was detected by next generation sequencing. The correlation of histologic subtype and clinical characteristics with EGFR mutation was analyzed. Results: Among 100 cases with lung adenocarcinoma, EGFR mutation was found in 49 cases (49.0%). Among all histologic subtypes, EGFR mutation was found in 23 cases (63.9%) with lepidic predominant adenocarcinoma, 5 cases (62.5%) with papillary predominant adenocarcinoma and 21 cases (46.7%) with acinar predominant adenocarcinoma. EGFR mutation was not found in micropapillary predominant adenocarcinoma and solid/mucinous predominant adenocarcinoma. EGFR mutation was significantly associated with histologic subtypes in stage I lung adenocarcinomas (P = 0.002). Especially, the frequency of EGFR mutation in lepidic predominant adenocarcinoma (60.8%) was higher than that in nonlepidic predominant adenocarcinoma (36.7%, P = 0.018), whereas the frequency of EGFR mutation in solid/mucinous predominant adenocarcinoma (20.0%) was lower than that in nonsolid/mucinous predominant adenocarcinoma (54.1%, P = 0.015). EGFR mutation was also associated with differentiation of lung adenocarcinoma (P = 0.001), and with no correlation with gender, age, smoking, tumor size and pleural metastasis (all P > 0.05). Conclusion: In stage Ⅰ lung adenocarcinomas, those with lepidic predominant adenocarcinoma or the presence of lepidic component have higher frequency of EGFR mutation. The differentiation of lung adenocarcinoma is related to EGFR mutation. DOI:10.3781/j.issn.1000-7431.2017.33.645