EGFR and non-small cell lung carcinoma: Several studies have reported that advanced NSCLC patients with EGFR exon 19 deletion had a longer overall survival (OS) and/or progression-free survival (PFS) following treatment with gefitinib or erlotinib compared with those with the L858R mutation [8], [9], [10], but this result has not been shown in all reports [12], [13], [14], [15], [16].