Epidermal Growth Factor Receptor Mutations In The International Association For The Study Of Lung Cancer/American Thoracic Society/European Respiratory Society Lung Adenocarcinoma Classification And Their Correlation Of The Clinicopathological Features

Objective:According to the International multidisciplinary classification of lung adenocarcinoma of the2011International Association for the Study of Lung Cancer, American Thoracic Society and the European Respiratory Society (new classification) to assess the correlation between the EGFR mutations and new classification,as well as its clinicopathological traits.Methods:292cases of lung adenocarcinoma and84cases of lung non-adenocarcinoma with detailed medical record and conventional wax block between2010-2012in tumor hospital of Shanxi province which included surgical specimens, puncture specimens and pleural effusion sediment samples had been collected. EGFR exon18-21mutations of all cases were detected by direct gene sequencing method and145surgical specimens were reclassified respectively with the new classification and WHO classification(2004).Results:There were123cases of mutation (42.1%) in292cases of lung adenocarcinoma and5cases of mutation(6.0%) in84cases of lung non-adenocarcinoma. Mutations wre found to be frequent in no smoking(P<0.001) and female (P<0.001) groups. Mutational situations of all histological subtypes in new classification were different(P=0.006). There was a close pertinence between EGFR mutations and specific subtypes comprising lepidic-predominant (P=0.024) micropapillary-predominant (P=0.011), presence of lepidic component (P<0.001), presence of papillary component (P=0.032) and presence of micropresence component subtypes (P=0.003). Conversely, rare mutations were in acinar-predominant (P=0.036) solid-predominant (P=0.020) and presence of variation component subtypes (P=0.030) Additionally, EGFR mutations in subtypes of WHO classification had no significant difference.Conclusion:(1) EGFR mutation rate is high specific indicator of lung adenocarcinoma.(2) Mutations majorly concentrated on the lack of exon19mutations and exon21point mutations., account for about90%.(3) EGFR mutations in Asian female non smokers are frequent and the Contact with other clinical pathological features is no statistical significance.(4) The new classification showing a correlation with molecular diagnostics, which advocated that the percentages of each subtype greater than5%in tumor tissue should be described in pathological diagnosis so-named5%incremental semi-quantitative method, need to be popularized.