Table 2.
The baseline characteristics of the training and validation cohorts.
| Characteristics | Number of patients (%) | P value | |
|---|---|---|---|
| Training cohort (n=2174) | Validation cohort (n=928) | ||
| Insurance status | |||
| Insured | 2161 (99.4) | 919 (99.0) | 0.37 |
| Uninsured | 13 (0.6) | 9 (1.0) | |
| Marital status | |||
| Married | 1083 (49.8) | 468 (50.4) | 0.784 |
| Unmarried | 1091 (50.2) | 460 (49.6) | |
| Race | |||
| White | 1541 (70.9) | 667 (71.9) | 0.856 |
| Black | 245 (11.3) | 101 (10.9) | |
| Other | 388 (17.8) | 160 (17.2) | |
| Sex | |||
| Male | 1277 (58.7) | 525 (56.6) | 0.28 |
| Female | 897 (41.3) | 403 (43.4) | |
| Primary site | |||
| Cardia/fundus | 693 (31.9) | 283 (30.5) | 0.776 |
| Body | 211 (9.7) | 86 (9.3) | |
| Antrum/pylorus | 589 (27.1) | 246 (26.5) | |
| Lesser/greater curvature | 262 (12.1) | 121 (13.0) | |
| Other | 419 (19.3) | 192 (20.7) | |
| Differentiation grade | |||
| I | 123 (5.7) | 46 (5.0) | 0.507 |
| II | 616 (28.3) | 263 (28.3) | |
| III | 1391 (64.0) | 593 (63.9) | |
| IV | 44 (2.0) | 26 (2.8) | |
| Histology | |||
| Adenocarcinoma | 1650 (75.9) | 687 (74.0) | 0.524 |
| Signet ring cell carcinoma | 288 (13.2) | 130 (14.0) | |
| Other | 236 (10.9) | 111 (12.0) | |
| AJCC Stage | |||
| I | 606 (27.9) | 241 (26.0) | 0.04 |
| II | 393 (18.1) | 183 (19.7) | |
| III | 585 (26.9) | 285 (30.7) | |
| IV | 590 (27.1) | 219 (23.6) | |
| T stage | |||
| T1 | 713 (32.8) | 290 (31.2) | 0.713 |
| T2 | 257 (11.8) | 106 (11.4) | |
| T3 | 650 (29.9) | 279 (30.1) | |
| T4 | 554 (25.5) | 253 (27.3) | |
| N stage | |||
| N0 | 1108 (51.0) | 465 (50.1) | 0.712 |
| N1 | 563 (25.9) | 253 (27.3) | |
| N2 | 231 (10.6) | 89 (9.6) | |
| N3 | 272 (12.5) | 121 (13.0) | |
| M stage | |||
| M0 | 1584 (72.9) | 709 (76.4) | 0.044 |
| M1 | 590 (27.1) | 219 (23.6) | |
| Surgery | |||
| No | 1224 (56.3) | 516 (55.6) | 0.749 |
| Yes | 950 (43.7) | 412 (44.4) | |
| Radiation | |||
| No/Unknown | 1662 (76.4) | 699 (75.3) | 0.53 |
| Yes | 512 (23.6) | 229 (24.7) | |
| Chemotherapy | |||
| No/Unknown | 1449 (66.7) | 603 (65.0) | 0.39 |
| Yes | 725 (33.3) | 325 (35.0) | |
| Bone metastases | |||
| No | 2129 (97.9) | 909 (98.0) | 1 |
| Yes | 45 (2.1) | 19 (2.0) | |
| Brain metastases | |||
| No | 2167 (99.7) | 928 (100.0) | 0.188 |
| Yes | 7 (0.3) | 0 (0.0) | |
| Liver metastases | |||
| No | 1894 (87.1) | 837 (90.2) | 0.019 |
| Yes | 280 (12.9) | 91 (9.8) | |
| Lung metastases | |||
| No | 2087 (96.0) | 900 (97.0) | 0.22 |
| Yes | 87 (4.0) | 28 (3.0) | |