Table 1 Clinicodemographic characteristics of patients in cohorts 1 and 2. Cohort 1 consisted of 18 lung cancer patients who underwent brain metastasectomy for metastatic brain tumors, while cohort 2 included 20 lung cancer patients with brain metastases who were treated with anti–PD-1 antibody (nivolumab or pembrolizumab). The two patient cohorts were independent of each other
Characteristics | Cohort 1 (N = 18) | Cohort 2 (N = 20) |
|---|---|---|
Age, median (range) | 59 (32–76) | 60 (33–77) |
Sex, n (%) | ||
 Male | 12 (66.7) | 10 (50) |
 Female | 6 (33.3) | 10 (50) |
Smoking, n (%) | ||
 Current smoker | 4 (22.2) | 7 (35.0) |
 Ex-smoker | 6 (33.3) | 3 (15.0) |
 Never smoked | 8 (44.4) | 10 (50.0) |
Stage at diagnosisa), n (%) | ||
 IA–IIB | 1 (5.6) | 4 (20.0) |
 IIIA–IV | 15 (83.3) | 16 (80.0) |
 Extensive disease (for small cell lung cancer) | 2 (11.1) | 0 (0.0) |
Histology, n (%) | ||
 Adenocarcinoma | 12 (66.7) | 15 (75.0) |
 Squamous cell carcinoma | 1 (5.6) | 4 (20.0) |
 Sarcomatoid carcinoma | 2 (11.1) | 1 (5.0) |
 Small cell lung cancer | 2 (11.1) | 0 (0.0) |
Mutational status, n (%) | ||
 EGFR | 3 (16.7) | 9 (45.0) |
 ALK | 2 (11.1) | 0 (0.0) |
Temporal relationship, n (%) | ||
 Synchronous | NA | 7 (35.0) |
 Metachronous | NA | 13 (65.0) |
Anti–PD-1 antibody treatment | ||
 Nivolumab | 14 (77.8) | NA |
 Pembrolizumab | 4 (22.2) | NA |
No. of chemotherapy treatments before EAP or brain surgery, n (%) | ||
 0 | 0 (0.0) | 8 (40.0) |
 1 | 6 (33.3) | 7 (35.0) |
 2 | 7 (38.9) | 2 (10.0) |
  ≥ 3 | 5 (27.8) | 3 (15.0) |
Cerebral irradiation before EAP or brain surgery, n (%) | ||
 Whole brain radiotherapy | 3 (16.7) | 2 (10.0) |
 Radiosurgery | 4 (22.2) | 2 (10.0) |
 Both | 3 (16.7) | 1 (5.0) |
Cerebral irradiation during EAP, n (%) | ||
 Whole brain radiotherapy | 3 (16.7) | NA |
 Radiosurgery | 0 (0.0) | NA |
 Both | 0 (0.0) | NA |