EGFR and adenocarcinoma: Moreover, a higher proportion of patients with adenocarcinoma histology received the EGFR testing compared to those with SCC (71.4% vs. 39.6%) is the second limitation; however this limitation implies that the influence of the presence of mutated-EGFRs on SBM occurrence compared to that of WT-EGFR had been possibly underestimated because patients with lung SCC have a smaller chance of harboring mutated-EGFRs (1-3%) and of experiencing BM than those with lung adenocarcinoma [32].