*3.1. Patient Characteristics*

The study enrolled 36 patients between July 2016 and May 2018, with 23 female patients (63.9%) with a median age of 80 years, and 19 patients (52.8%) who were ≥80 years old. The histological types were adenocarcinoma in 35 patients (97.2%) and a mixed type with small cell lung cancer in only 1 patient. Based on the 7th edition of the AJCC system for staging lung cancer, 25 cases (69.4%) were considered stage IV, 10 cases (27.8%) involved relapse after surgery, and 1 case (2.8%) was considered stage IIIB. Among the enrolled patients, 30.6% were former smokers. The EGFR gene mutations involved the exon 20 T790M mutation in all cases, as well as exon 19 deletion in 22 cases (61.1%) and the exon 21 L858R point mutation in 11 cases (30.6%). Brain metastasis was detected in 15 patients (41.7%) (Table 1).


**Table 1.** Patient characteristics.


**Table 1.** *Cont.*

PS: performance status, SCLC: small cell lung cancer.
