Table 1.
Demographic, treatment, and pathologic variables in the training and validation cohorts
| Training cohort (n=325) |
Validation cohort (n=186) |
p-value | |
|---|---|---|---|
| Age, years (mean +/− s.d.) | 61.4 ± 11.6 | 58.6 ± 11.8 | 0.010 |
| ≤ 60 | 139 (48.2%) | 100 (53.8%) | 0.017 |
| > 60 | 186 (57.2%) | 86 (46.2%) | |
| Sex | 0.018 | ||
| Male | 195 (60.0%) | 131 (70.4%) | |
| Female | 130 (40.0%) | 55 (29.6%) | |
| Body mass index, kg/m2 (mean +/− s.d.) | 26.7 ± 4.7 | 23.2 ± 3.8 | <0.001 |
| Race | <0.001 | ||
| Caucasian | 233 (71.7%) | 88 (47.3%) | |
| Asian/other | 92 (28.3%) | 98 (52.7%) | |
| Type of gastectomy | <0.001 | ||
| Distal gastrectomy | 161 (49.5%) | 40 (21.5%) | |
| Total gastrectomy | 154 (47.4%) | 146 (78.5%) | |
| Proximal gastrectomy | 10 (3.1%) | 0 (0%) | |
| Surgical approach | <0.001 | ||
| Open | 283 (87.1%) | 91 (48.9%) | |
| Minimally invasive | 42 (12.9%) | 95 (51.1%) | |
| Post-operative adjuvant therapy | 0.001 | ||
| None | 168 (51.7%) | 92 (49.5%) | |
| Adjuvant chemotherapy | 136 (41.8%) | 94 (50.5%) | |
| Adjuvant chemoradiotherapy | 21 (6.5%) | 0 (0%) | |
| Tumour size, cm (mean +/− s.d.) | 4.0 ± 3.3 | 5.7 ± 2.6 | <0.001 |
| Tumour location | 0.001 | ||
| Lower third | 135 (41.5%) | 46 (24.7%) | |
| Middle third | 75 (23.1%) | 56 (30.1%) | |
| Upper third | 102 (31.4%) | 68 (36.6%) | |
| More than two parts | 13 (4.0%) | 16 (8.6%) | |
| Lauren type | - | - | |
| Intestinal | 156 (48.0%) | - | |
| Diffuse | 107 (32.9%) | - | |
| Mixed/unknown | 62 (19.1%) | - | |
| Differentiation | <0.001 | ||
| Differentiated | 173 (53.2%) | 69 (37.1%) | |
| Undifferentiated/unknown | 152 (46.8%) | 117 (62.9%) | |
| Vascular invasion | - | ||
| Yes | 163 (50.2%) | - | |
| No | 162 (49.8%) | - | |
| Perineural invasion | - | ||
| Yes | 159 (48.9%) | - | |
| No | 166 (51.1%) | - | |
| Treatment effect | - | ||
| 0–49% | 192 (59.1%) | - | |
| 50–89% | 73 (22.5%) | - | |
| 90–100% | 60 (18.5%) | - | |
| ≥16 lymph nodes examined | 301 (92.6%) | 179 (96.2%) | 0.099 |
| Lymph nodes examined (mean +/− s.d.) | 26.6 ± 11.9 | 31.4 ± 11.9 | <0.001 |
| Positive lymph nodes (mean +/− s.d.) | 3.2 ± 5.6 | 5.7 ± 2.6 | <0.001 |
| ypT status | <0.001 | ||
| T0 | 33 (10.2%) | 1 (0.5%) | |
| T1 | 39 (12.0%) | 17 (9.2%) | |
| T2 | 41 (12.6%) | 33 (17.7%) | |
| T3 | 127 (39.0%) | 62 (33.3%) | |
| T4 | 85 (26.2%) | 73 (39.3%) | |
| ypN status | <0.001 | ||
| N0 | 147 (45.2%) | 55 (29.6%) | |
| N1 | 70 (21.5%) | 31 (16.7%) | |
| N2 | 48 (14.8%) | 36 (19.4%) | |
| N3a | 49 (15.1%) | 45 (24.2%) | |
| N3b | 11 (3.4%) | 19 (10.2%) | |
| ypTNM stage | <0.001 | ||
| ypT0N0/+ | 33 (10.2%) | 1 (0.5%) | |
| I | 51 (15.7%) | 26 (14.0%) | |
| II | 125 (38.5%) | 57 (30.7%) | |
| III | 116 (35.7%) | 102 (54.8%) | |