Table 1

Unadjusted patient characteristics for the chemotherapy after PD-1 inhibitor treatment (CAP) and control cohorts

CharacteristicCAP cohort
(n=243)
Control cohort
(n=1196)
P value*
Age, years†‡
 Median (range)68 (38–86)69 (30–87)0.01
 <70150 (61.7)655 (54.8)0.06
 ≥7093 (38.3)539 (45.1)
Sex
 Male169 (69.5)867 (72.5)0.35
 Female74 (30.5)329 (27.5)
Smoking status§
 Never60 (24.7)278 (23.2)0.78
 Past102 (42.0)487 (40.7)
 Current81 (33.3)423 (35.4)
 Unknown0 (0.0)8 (0.7)
Histology
 Adenocarcinoma161 (66.3)859 (71.8)0.02
 Squamous cell carcinoma73 (30.0)263 (22.0)
 Other9 (3.7)74 (6.2)
EGFR mutation status
 Positive28 (11.5)201 (16.8)0.04¶
 Negative177 (72.8)839 (70.2)
 Unknown38 (15.6)156 (13.0)
ALK rearrangement status
 Positive8 (3.3)13 (1.1)0.02¶
 Negative177 (72.8)837 (70.0)
 Unknown58 (23.9)346 (28.9)
PD-L1 TPS**
 ≥50%23 (9.5)33 (2.8)0.008
 1%–49%41 (16.9)76 (6.4)
 <1%32 (13.2)115 (9.6)
 Unknown147 (60.5)972 (81.3)
ECOG PS†††
 0–1197 (81.1)1038 (86.8)0.054‡‡
 ≥234 (14.0)111 (9.3)
 Unknown12 (4.9)46 (3.8)
Stage§§
 III31 (12.8)156 (13.0)0.94
 IV170 (70.0)812 (67.9)
 Recurrence after surgery33 (13.6)175 (14.6)
 Recurrence after CRT9 (3.7)53 (4.4)
Brain metastasis†
 Yes65 (26.7)247 (20.7)0.04
 No178 (73.3)949 (79.3)
Type of chemotherapy
 Docetaxel105 (43.2)778 (65.1)<0.001
 Docetaxel+ramucirumab77 (31.7)94 (7.9)
 S-149 (20.2)174 (14.5)
 Pemetrexed12 (4.9)150 (12.5)
  • Data are presented as n (%) with the exception of median age.

  • *P values were determined with the Wilcoxon test or Fisher’s exact test as appropriate.

  • †At the time of initiation of docetaxel with or without ramucirumab, S-1 or pemetrexed.

  • ‡Two patients in the control cohort had missing data.

  • §Never smokers were defined as individuals who had smoked <100 cigarettes; past smokers as those who had smoked ≥100 cigarettes but had quit >1 year prior to diagnosis; and current smokers as those who had smoked ≥100 cigarettes including at least one within the year prior to diagnosis.

  • ¶P values are for comparison between patients positive for EGFR or ALK alterations and those negative or of unknown status.

  • **Data for PD-L1 expression in tumor cells were obtained by immunohistochemistry according to the standard practice of each center.

  • ††One patient in the control cohort had missing data.

  • ‡‡P value is for comparison between PS of 0–1 and PS of 2–4 or unknown.

  • §§All patients were classified on the basis of clinical stage according to the seventh edition of the TNM classification.

  • CRT, chemoradiotherapy; ECOG PS, Eastern Cooperative Oncology Group performance status; TPS, tumor proportion score.