Patients
This retrospective, nonrandomized study reviewed the electronic medical records (EMRs) of 334 advanced NSCLC patients who underwent EGFR-TKI treatment between 2003 and 2019 at the Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Japan. The inclusion criteria were as follows: (1) age >=65 years; (2) histologically or cytologically confirmed unresectable locally advanced (stage III), metastatic (stage IV), or recurrent EGFR -mutated NSCLC; (3) EGFR-TKI (only gefitinib, erlotinib, afatinib, or osimertinib) administration, either as first-line or as later-line therapy; and (4) evaluable for concomitant medications at EGFR-TKI treatment initiation.
We obtained the following baseline characteristics from EMRs: sex; age; body mass index (BMI); smoking status (Brinkman index = daily number of cigarettes × years); Eastern Cooperative Oncology Group–Performance Status (ECOG-PS); Charlson Comorbidities Index (CCI), including NSCLC itself; and Gustave Roussy Immune Score (GRIm-Score) calculated from serum albumin levels; lactate dehydrogenase (LDH); neutrophil-to-lymphocyte ratio (NLR)[28]; histological subtype;EGFR mutation status and subtypes; clinical staging (UICC Tumor, Node, Metastasis [TNM] Classification of Malignant Tumors, 8th edition)[29]; number of organs involved in metastasis; lines of EGFR-TKI treatment; and concomitant medications.