Table 1 Clinical characteristics of patients in the training, internal, and external validation cohorts.
|  | Training cohort (n = 203) | Internal validation cohort (n = 204) | External validation cohort (n = 333) | ||||||
|---|---|---|---|---|---|---|---|---|---|
|  | Patients | Low PS (n = 77) | High PS (n = 126) | Patients | Low PS (n = 63) | High PS (n = 141) | Patients | Low PS (n = 104) | High PS (n = 229) |
Age (years) | |||||||||
< 65 | 129 (63.5) | 51 (66.2) | 78 (61.9) | 131 (64.2) | 43 (68.3) | 88 (62.4) | 225 (67.6) | 70 (67.3) | 155 (67.7) |
≥ 65 | 74 (36.5) | 26 (33.8) | 48 (38.1) | 73 (35.8) | 20 (31.7) | 53 (37.6) | 108 (32.4) | 34 (32.7) | 74 (32.3) |
Sex | |||||||||
Female | 84 (41.4) | 37 (48.1) | 47 (37.3) | 81 (39.7) | 30 (47.6) | 51 (36.2) | 142 (42.6) | 41 (39.4) | 101 (44.1) |
Male | 119 (58.6) | 40 (51.9) | 79 (62.7) | 123 (60.3) | 33 (52.4) | 90 (63.8) | 191 (57.4) | 63 (60.6) | 128 (55.9) |
Tumor location | |||||||||
Colon | 112 (55.2) | 42 (54.5) | 70 (55.6) | 106 (52.0) | 35 (55.6) | 71 (50.4) | 195 (58.6) | 65 (62.5) | 130 (56.8) |
Rectum | 91 (44.8) | 35 (45.5) | 56 (44.4) | 98 (48.0) | 28 (44.4) | 70 (49.6) | 138 (41.4) | 39 (37.5) | 99 (43.2) |
Histology type | |||||||||
High | 158 (77.8) | 61 (79.2) | 97 (77.0) | 162 (79.4) | 54 (85.7) | 108 (76.6) | 260 (78.1) | 89 (85.6) | 171 (74.7) |
Low | 42 (20.7) | 16 (20.8) | 26 (20.6) | 40 (19.6) | 7 (11.1) | 33 (23.4) | 57 (17.1) | 13 (12.5) | 44 (19.2) |
Missing | 3 (1.5) | 0 (0.0) | 3 (2.4) | 2 (1.0) | 2 (3.2) | 0 (0.0) | 16 (4.8) | 2 (1.9) | 14 (6.1) |
pT stage | |||||||||
pT1 | 2 (1.0) | 0 (0.0) | 2 (1.6) | 1 (0.5) | 0 (0.0) | 1 (0.7) | 1 (0.3) | 1 (1.0) | 0 (0.0) |
pT2 | 5 (2.5) | 3 (3.9) | 2 (1.6) | 11 (5.4) | 3 (4.8) | 8 (5.7) | 9 (2.7) | 2 (1.9) | 7 (3.1) |
pT3 | 174 (85.7) | 67 (87.0) | 107 (84.9) | 166 (81.4) | 53 (84.1) | 113 (80.1) | 274 (82.3) | 87 (83.7) | 187 (81.7) |
pT4 | 22 (10.8) | 7 (9.1) | 15 (11.9) | 26 (12.7) | 7 (11.1) | 19 (13.5) | 49 (14.7) | 14 (13.5) | 35 (15.3) |
pN stage | |||||||||
pN0 | 97 (47.8) | 49 (63.6) | 48 (38.1) | 101 (49.5) | 36 (57.1) | 65 (46.1) | 172 (51.7) | 55 (52.9) | 117 (51.1) |
pN1 | 82 (40.4) | 21 (27.3) | 61 (48.4) | 80 (39.2) | 22 (34.9) | 58 (41.1) | 107 (32.1) | 38 (36.5) | 69 (30.1) |
pN2 | 24 (11.8) | 7 (9.1) | 17 (13.5) | 23 (11.3) | 5 (7.9) | 18 (12.8) | 54 (16.2) | 11 (10.6) | 43 (18.8) |
Stage | |||||||||
II | 97 (47.8) | 49 (63.6) | 48 (38.1) | 101 (49.5) | 36 (57.1) | 65 (46.1) | 172 (51.7) | 55 (52.9) | 117 (51.1) |
III | 106 (52.2) | 28 (36.4) | 78 (61.9) | 103 (50.5) | 27 (42.9) | 76 (53.9) | 161 (48.3) | 49 (47.1) | 112 (48.9) |
Number of lymph nodes examined | |||||||||
< 12 | 15 (7.4) | 6 (7.8) | 9 (7.1) | 11 (5.4) | 2 (3.2) | 9 (6.4) | 117 (35.1) | 35 (33.7) | 82 (35.8) |
≥ 12 | 188 (92.6) | 71 (92.2) | 117 (92.9) | 193 (94.6) | 61 (96.8) | 132 (93.6) | 216 (64.9) | 69 (66.3) | 147 (64.2) |
CEA concentration | |||||||||
< 5 | 136 (67.0) | 53 (68.8) | 83 (65.9) | 122 (59.8) | 42 (66.7) | 80 (56.7) | 193 (58.0) | 61 (58.7) | 132 (57.6) |
≥ 5 | 57 (28.1) | 18 (23.4) | 39 (31.0) | 71 (34.8) | 18 (28.6) | 53 (37.6) | 130 (39.0) | 36 (34.6) | 94 (41.0) |
Missing | 10 (4.9) | 6 (7.8) | 4 (3.2) | 11 (5.4) | 3 (4.8) | 8 (5.7) | 10 (3.0) | 7 (6.7) | 3 (1.3) |
Adjuvant chemotherapy | |||||||||
Yes | 109 (53.7) | 49 (63.6) | 60 (47.6) | 104 (51.0) | 30 (47.6) | 74 (52.5) | 227 (68.2) | 74 (71.2) | 153 (66.8) |
No | 63 (31.0) | 20 (26.0) | 43 (34.1) | 74 (36.3) | 23 (36.5) | 51 (36.2) | 75 (22.5) | 20 (19.2) | 55 (24.0) |
Missing | 31 (15.3) | 8 (10.4) | 23 (18.3) | 26 (12.7) | 10 (15.9) | 16 (11.3) | 31 (9.3) | 10 (9.6) | 21 (9.2) |
Follow-up, years | 8.68 (5.55−9.68) | 9.05 (7.98−9.69) | 8.55 (4.20−9.66) | 9.03 (6.52−9.9) | 9.22 (8.05−10.37) | 8.74 (6.03−9.69) | 6.39 (2.89−7.36) | 6.48 (3.02−7.46) | 6.06 (2.69−7.37) |
