Correlation of EGFR mutation and histological subtype according to the IASLC/ATS/ERS classification of lung adenocarcinoma.

OBJECTIVE

To evaluate the correlation of EGFR mutation and histological subtypes of lung adenocarcinoma based on the IASLC/ATS/ERS classification.

METHODS

EGFR exons 18-21 of 206 resected lung adenocarcinoma specimens were analyzed with pyrosequecing, then the differences between histological subtypes and EGFR mutation were compared.

RESULTS

EGFR mutation was detected in 123 specmens, most of which were papillary and acinar predominant adenocarcinoma. EGFR mutation rate of the specimens with papillary, acinar or lepidic component was higher than without these components (P < 0.05), and with solid or mucinous component was lower than that without the component (P < 0.05). EGFR mutation in solid predominant mixed other subtypes was more commonly found than that of pure solid component (P=0.018).

CONCLUSIONS

The presence of well-differentiated components in lung adenocarcinoma, such as lepidic, papillary and acinar, indicates a higher EGFR mutation rate, while the solid and mucinous component indicate a lower EGFR mutation rate. There is heterogeneity of EGFR mutation in lung adenocarcinoma.