TABLE 1.
Characteristics of the study population.
| Total | Increased REC | No increased REC | p‐value | ||
|---|---|---|---|---|---|
| n = 151 | n = 87 | n = 64 | |||
| Age, years | Mean, (SD) | 69 (9) | 70 (9) | 69 (9) | 0.6 a |
| Sex, n (%) | Male | 117 (77) | 67 (77) | 50 (78) | 1.0 b |
| Female | 34 (23) | 20 (23) | 14 (22) | ||
| Smoking history, n (%) | Yes | 118 (78) | 64 (74) | 54 (84) | 0.2 b |
| No | 28 (19) | 19 (22) | 9 (14) | ||
| ECOG PS, n (%) | 0–1 | 136 (90) | 80 (92) | 56 (88) | 0.4 b |
| 2–4 | 15 (10) | 7 (8) | 8 (13) | ||
| Stage, n (%) | Recurrence | 21 (14) | 12 (14) | 9 (14) | 0.8 c |
| III | 30 (20) | 19 (22) | 11 (17) | ||
| IV | 100 (66) | 56 (64) | 44 (69) | ||
| Histological type, n (%) | Adeno | 89 (59) | 50 (57) | 39 (61) | 0.8 c |
| Squamous | 43 (28) | 27 (31) | 16 (25) | ||
| Others | 19 (13) | 10 (11) | 9 (14) | ||
| PD‐L1, n (%) | <1% | 30 (20) | 13 (15) | 17 (27) | 0.06 c |
| ≥1% | 118 (78) | 72 (83) | 46 (72) | ||
| Missing | 3 (2) | 2 (2) | 1 (2) | ||
| Treatment line, n (%) | 1 | 40 (26) | 27 (31) | 13 (20) | 0.1 b |
| >1 | 111 (74) | 60 (69) | 51 (80) | ||
| ICI drug, n (%) | Pembrolizumab | 117 (77) | 71 (82) | 46 (72) | 0.2 c |
| Nivolumab | 33 (22) | 16 (18) | 17 (27) | ||
| Atezolizumab | 1 (1) | 0 (0) | 1 (2) | ||
| Liver metastasis, n (%) | No | 138 (91) | 80 (92) | 58 (91) | 0.7 c |
| Yes | 13 (9) | 7 (8) | 6 (9) | ||
| Brain metastasis, n (%) | No | 117 (77) | 64 (74) | 53 (83) | 0.2 c |
| Yes | 34 (23) | 23 (26) | 11 (17) | ||
| Steroids, n (%) | No | 142 (94) | 81 (93) | 61 (95) | 0.4 b |
| Yes | 9 (6) | 6 (7) | 3 (5) | ||
| Tumor size, mm | Mean (SD) | 43 (23) | 41 (22) | 45 (25) | 0.2 a |
| White blood count/μL | Mean (SD) | 6826 (2597) | 6607 (2262) | 7124 (2987) | 0.2 a |
| Neutrophils/μL | Mean (SD) | 4647 (2231) | 4509 (1983) | 4833 (2535) | 0.4 a |
| Neutrophils, % | Mean (SD) | 66 (9) | 67 (9) | 66 (9) | 0.6 a |
| Lymphocytes/μL | Mean (SD) | 1440 (581) | 1426 (533) | 1458 (645) | 0.7 a |
| Lymphocytes, % | Mean (SD) | 22 (9) | 23 (8) | 22 (9) | 0.6 a |
| Eosinophils/μL | Mean, (SD) | 179 (187) | 144 (126) | 226 (239) | 0.01 a |
| Eosinophils, % | Mean (SD) | 2.7 (2.5) | 2.3 (2.0) | 3.1 (3.9) | 0.01 a |
| sNLR, ratio | Mean (SD) | 3.6 (2.0) | 3.6 (1.9) | 3.7 (2.1) | 0.6 a |
| CRP, mg/dL | Mean (SD) | 2.3 (3.1) | 2.0 (2.6) | 2.8 (3.7) | 0.1 a |
| Alb, g/dL | Mean (SD) | 3.5 (0.6) | 3.6 (0.6) | 3.4 (0.7) | 0.02 a |
| 4w white blood count/μL | Mean (SD) | 7929 (5170) | 6709 (2633) | 9588 (7023) | 0.003 a |
| 4w neutrophils/μL | Mean (SD) | 5625 (4993) | 4408 (2455) | 7278 (6806) | <0.001 a |
| 4w neutrophils, % | Mean (SD) | 67 (12) | 63 (11) | 71 (13) | <0.001 a |
| 4w lymphocytes/μL | Mean (SD) | 1516 (694) | 1492 (617) | 1549 (791) | 0.6 a |
| 4w lymphocytes, % | Mean (SD) | 22 (10) | 24 (9) | 20 (11) | 0.01 a |
| 4w eosinophils/μL | Mean (SD) | 218 (246) | 280 (285) | 134 (143) | <0.001 a |
| 4w eosinophils, % | Mean (SD) | 3.3 (3.4) | 4.4 (3.8) | 1.8 (1.9) | <0.001 a |
| 4w sNLR, ratio | Mean (SD) | 5.2 (7.5) | 4.2 (6.4) | 6.6 (8.6) | 0.06 a |
Abbreviations: Alb, albumin; CRP, C‐reactive protein; ECOG PS, Eastern Cooperative Oncology Group performance Ssatus; ICI, immune checkpoint inhibitor; PD‐L1, programmed death ligand 1; REC, relative eosinophil count after 4 weeks of immune checkpoint inhibitor treatment; sNLR, neutrophil‐to‐lymphocyte ratio in serum; 4w, 4 weeks later.
a
Independent samples t‐test.
b
Fisher's exact test.
c
Chi‐squared test.