EGFR and adenocarcinoma: Some of the studies report that the prevalence of EGFR mutation is more common in advanced stages of adenocarcinoma particularly true in cases of extrathoracic metastasis [19], while few report that EGFR mutation occurs during the early stage of pathogenesis of adenocarcinoma hence presence of EGFR mutation does not suggest advanced diseases, which was the finding in our study also, where there was no significant association between TNM stage and mutation rate and type.