1. Demographic and clinicopathological characteristics of patients.
| Variables | n (%) | P | ||
| All patients | Training cohort | Validation cohort | ||
| NOS, not otherwise specified; LNR, lymph node rate; LODDS, log odds of positive lymph nodes. | ||||
| Total | 1,365 (100) | 687 (50.3) | 678 (49.7) | |
| Sex | 0.169 | |||
| Female | 668 (48.9) | 323 (47.0) | 345 (50.9) | |
| Male | 697 (51.1) | 364 (53.0) | 333 (49.1) | |
| Age (year) | 0.395 | |||
| <45 | 192 (14.1) | 88 (12.8) | 104 (15.3) | |
| 45−59 | 458 (33.6) | 232 (33.8) | 226 (33.3) | |
| ≥60 | 715 (52.4) | 367 (53.4) | 348 (51.3) | |
| Race | 0.943 | |||
| Black | 165 (12.1) | 81 (11.8) | 84 (12.4) | |
| Other | 314 (23.0) | 159 (23.1) | 155 (22.9) | |
| White | 886 (64.9) | 447 (65.1) | 439 (64.7) | |
| Grade | 0.076 | |||
| I | 1 (0.1) | 1 (0.1) | 0 (0) | |
| II | 36 (2.6) | 21 (3.1) | 15 (2.2) | |
| III | 1,287 (94.3) | 638 (92.9) | 649 (95.7) | |
| IV | 41 (3.0) | 27 (3.9) | 14 (2.1) | |
| Size (cm) | 0.195 | |||
| <3.5 | 522 (38.2) | 247 (36.0) | 275 (40.6) | |
| 3.5−6.8 | 492 (36.0) | 260 (37.8) | 232 (34.2) | |
| >6.8 | 351 (25.7) | 180 (26.2) | 171 (25.2) | |
| Stage | 0.292 | |||
| I | 317 (23.2) | 149 (21.7) | 168 (24.8) | |
| II | 321 (23.5) | 155 (22.6) | 166 (24.5) | |
| III | 587 (43.0) | 307 (44.7) | 280 (41.3) | |
| IV | 140 (10.3) | 76 (11.1) | 64 (9.4) | |
| T stage | 0.224 | |||
| T1 | 269 (19.7) | 129 (18.8) | 140 (20.6) | |
| T2 | 155 (11.4) | 80 (11.6) | 75 (11.1) | |
| T3 | 449 (32.9) | 226 (32.9) | 223 (32.9) | |
| T4a | 395 (28.9) | 212 (30.9) | 183 (27.0) | |
| T4b | 97 (7.1) | 40 (5.8) | 57 (8.4) | |
| N stage | 0.069 | |||
| N0 | 472 (34.6) | 216 (31.4) | 256 (37.8) | |
| N1 | 208 (15.2) | 112 (16.3) | 96 (14.2) | |
| N2 | 233 (17.1) | 115 (16.7) | 118 (17.4) | |
| N3a | 284 (20.8) | 159 (23.1) | 125 (18.4) | |
| N3b | 168 (12.3) | 85 (12.4) | 83 (12.2) | |
| M stage | 0.369 | |||
| M0 | 1,225 (89.7) | 611 (88.9) | 614 (90.6) | |
| M1 | 140 (10.3) | 76 (11.1) | 64 (9.4) | |
| Site | 0.498 | |||
| C16.0-cardia, NOS | 178 (13.0) | 90 (13.1) | 88 (13.0) | |
| C16.1-fundus of stomach | 36 (2.6) | 17 (2.5) | 19 (2.8) | |
| C16.2-body of stomach | 160 (11.7) | 84 (12.2) | 76 (11.2) | |
| Gastric antrum (including pylorus) | 456 (33.4) | 219 (31.9) | 237 (35.0) | |
| C16.5-lesser curvature of stomach, NOS | 189 (13.8) | 105 (15.3) | 84 (12.4) | |
| C16.6-greater curvature of stomach, NOS | 76 (5.6) | 43 (6.3) | 33 (4.9) | |
| Stomach, NOS | 270 (19.8) | 129 (18.8) | 141 (20.8) | |
| LNR | 0.400 | |||
| LNR1 | 610 (44.7) | 295 (42.9) | 315 (46.5) | |
| LNR2 | 436 (31.9) | 224 (32.6) | 212 (31.3) | |
| LNR3 | 319 (23.4) | 168 (24.5) | 151 (22.3) | |
| LODDS | 0.447 | |||
| LODDS1 | 471 (34.5) | 223 (32.5) | 248 (36.6) | |
| LODDS2 | 318 (23.3) | 163 (23.7) | 155 (22.9) | |
| LODDS3 | 364 (26.7) | 191 (27.8) | 173 (25.5) | |
| LODDS4 | 212 (15.5) | 110 (16.0) | 102 (15.0) | |