Table 1 Baseline characteristics of the patients
|  | Eligible group (n = 242) | Ineligible group (n = 123) | All patients (n = 365) | P-value |
|---|---|---|---|---|
Age ― years | 70.1 ± 2.87 | 76.0 ± 5.12 | 72.1 ± 4.68 | 1.8 × 10–23 |
Male sex ― n (%) | 209 (86) | 106 (86) | 315 (86) | 1.00 |
ECOG PS ― n (%) |  |  |  | 7.6 × 10–8 |
 0 | 188 (78) | 71 (58) | 259 (71) |  |
 1 | 54 (22) | 40 (33) | 94 (26) |  |
 2–4 | 0 (0) | 12 (10) | 12 (3) |  |
Charlson comorbidity index ― n (%) |  |  |  | 9.0 × 10–5 |
 Low: 0 | 134 (55) | 41 (33) | 175 (48) |  |
 Medium: 1–2 | 88 (36) | 59 (48) | 147 (40) |  |
 High: 3–6 | 20 (8) | 23 (19) | 43 (12) |  |
Tumor site ― n (%) |  |  |  | 0.96 |
 Ut | 36 (15) | 17 (14) | 53 (15) |  |
 Mt | 118 (49) | 62 (50) | 180 (49) |  |
 Lt | 88 (36) | 44 (36) | 132 (36) |  |
T stage ― n (%) |  |  |  | 0.60 |
 T1b | 26 (11) | 10 (8) | 36 (10) |  |
 T2 | 48 (20) | 29 (23) | 77 (21) |  |
 T3 | 168 (69) | 84 (68) | 252 (69) |  |
N stage ― n (%) |  |  |  | 0.65 |
 N0 | 69 (29) | 37 (30) | 106 (29) |  |
 N1 | 107 (44) | 47 (38) | 154 (42) |  |
 N2 | 52 (22) | 29 (24) | 81 (22) |  |
 N3 | 14 (6) | 10 (8) | 24 (7) |  |
Clinical stage ― n (%) |  |  |  | 0.32 |
 IB | 24 (10) | 17 (14) | 41 (11) |  |
 IIA/IIB | 85 (35) | 35 (29) | 120 (33) |  |
 IIIA/IIIB/IIIC | 133 (55) | 71 (58) | 204 (56) |  |
Treatment |  |  |  | 1.9 × 10–13 |
 NAC followed by surgery ― n (%) | 169 (70) | 40 (33) | 209 (57) |  |
  Curative resection ― n (%) | 161 (67) | 39 (32) | 200 (55) | 1.00 |
 Surgery ― n (%) | 27 (11) | 28 (23) | 55 (15) |  |
  Curative resection ― n (%) | 25 (10) | 26 (21) | 51 (14) | 1.00 |
 CRT ― n (%) | 36 (15) | 35 (28) | 71 (20) |  |
  Radiation dose ― n (%) |  |  |  | 5.1 × 10–3 |
   ≥ 50 Gy | 36 (15) | 28 (23) | 64 (18) |  |
   < 50 Gy | 0 (0) | 4 (3) | 4 (1) |  |
   Unknown | 0 (0) | 3 (2) | 3 (1) |  |
 Radiation ― n (%) | 3 (1) | 19 (15) | 22 (6) |  |
  Radiation dose ― n (%) |  |  |  | 0.26 |
   ≥ 50 Gy | 2 (1) | 18 (15) | 20 (5) |  |
   < 50 Gy | 1 (0) | 1 (1) | 2 (1) |  |
 Chemotherapy ― n (%) | 7 (3) | 1 (1) | 8 (2) |  |
Blood test | ||||
 White blood cell count ― per μL | 6,691 ± 1,971 | 6,337 ± 2,772 | 6,572 ± 2,275 | 0.21 |
 Hemoglobin ― g/dL | 13.3 ± 1.46 | 12.5 ± 1.68 | 13.1 ± 1.59 | 2.0 × 10–6 |
 Platelet count ― × 103 per μL | 235 ± 63.3 | 224 ± 78.9 | 231 ± 69.0 | 0.19 |
 Albumin ― mg/dL | 4.03 ± 0.48 | 3.85 ± 0.46 | 3.97 ± 0.48 | 3.3 × 10–4 |
 Total bilirubin ― mg/dL | 0.66 ± 0.27 | 0.81 ± 0.56 | 0.71 ± 0.40 | 5.9 × 10–3 |
 Creatinine ― mg/dL | 0.82 ± 0.18 | 0.90 ± 0.33 | 0.85 ± 0.24 | 8.9 × 10–3 |