EGFR and non-small cell lung carcinoma: Therefore, regarding the setting of the statistical analysis in this study, the threshold of ORR was estimated by referring to the lower limit of the CI for the ORR in the previous retrospective study for patients with EGFR T790M mutation-positive NSCLC and a poor P S[16] and our prospective observational study of first-line osimertinib for patients with poor PS[21].