Correlation between EML4-ALK, EGFR and clinicopathological features based on IASLC/ATS/ERS classification of lung adenocarcinoma

To investigate the correlation between echinodermmicro tubule associated protein-like 4 (EML4)-anaplasticlymphomakinase (ALK), epidermal growth factor receptor (EGFR) and clinicopathological features in patients diagnosed with lung adenocarcinoma according to International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) international multidisciplinary classification of lung adenocarcinoma. Ninety patients diagnosed with lung adenocarcinoma underwent surgical pathological classification. Ventana immunohistochemical staining of the EML4-ALK was performed. The mutation of EGFR and EML4-ALK was detected by real-time polymerase chain reaction (RT-PCR) using the amplification refractory mutation system. The positive rate of EML4-ALK mutation was calculated as 6.7% (6/90), dominantly occurring in patients aged < 60 years. However, it was not correlated with the gender, smoking history, maximal tumor diameter, pleural invasion, lymphatic metastasis, or clinical staging. EML4-ALK fusion gene mutation was mainly associated with the predominant subtypes of acinar and solid tumors with mucin secretion. The mutation rate of EGFR was 60% (27/45). EGFR gene mutation mainly occurred in the female, those with no smoking history and tumor size < 3 cm, whereas it had no association with age, pleural invasion, lymphatic metastasis, or clinical staging. It was histologically characterized with micropapillary, lepidic, and papillary subtypes. The mutation rate of EML4-ALK is relatively high in lung adenocarcinoma patients aged<60 years, pathologically characterized with acinar and solid subtypes with mucin secretion. Female patients with no smoking habit, tumor size<3 cm, pathologically characterized with micropapillary, lepidic, and papillary subtypes had a high mutation rate of EGFR.