Table 1.
Demographic and clinicopathological characteristics of patients.
| Various | Training group | Validation group | ||||
|---|---|---|---|---|---|---|
| OPM (+) | OPM (-) | P value | OPM (+) | OPM (-) | P value | |
| Gender, no. (%) | 0.555 | 0.135 | ||||
| Female | 21 (28.8) | 146 (32.2) | 9 (56.3) | 48 (36.9) | ||
| Male | 52 (71.2) | 307 (67.8) | 7 (43.8) | 82 (63.1) | ||
| Age, no. (%) | 0.900 | 0.512 | ||||
| <60 | 36 (49.3) | 227 (50.1) | 7 (43.8) | 61 (46.9) | ||
| ≥60 | 37 (50.7) | 226 (49.9) | 9 (56.3) | 69 (53.1) | ||
| Location, no. (%) | 0.209 | 0.430 | ||||
| Lower third | 36 (49.3) | 259 (57.2) | 11 (68.8) | 74 (56.9) | ||
| Upper/middle third | 37 (50.7) | 194 (42.8) | 5 (31.3) | 56 (43.1) | ||
| Size, no. (%) | <0.001 | 0.003 | ||||
| <5 cm | 20 (27.4) | 311 (68.7) | 5 (31.3) | 93 (71.5) | ||
| ≥5 cm | 53 (72.6) | 142 (31.3) | 11 (68.8) | 37 (28.5) | ||
| Pathological type, no. (%) | 0.971 | 0.622 | ||||
| Adenocarcinoma | 62 (84.9) | 384 (84.8) | 14 (87.5) | 120 (92.3) | ||
| Nonadenocarcinoma | 11 (15.1) | 69 (15.2) | 2 (12.5) | 10 (7.7) | ||
| Differentiated degree, no. (%) | <0.001 | 0.102 | ||||
| High/middle | 9 (12.3) | 203 (44.8) | 5 (31.3) | 67 (51.5) | ||
| Poorly | 64 (87.7) | 250 (55.2) | 11 (68.8) | 63 (48.5) | ||
| Depth of invasion, no. (%) | <0.001 | <0.001 | ||||
| Nonserosal invasion | 13 (17.8) | 305 (67.3) | 3 (18.8) | 85 (65.4) | ||
| Serosal invasion | 60 (82.2) | 148 (32.7) | 13 (81.3) | 45 (34.6) | ||
OPM (+): with occult peritoneal metastasis. OPM (-): without occult peritoneal metastasis. Gastric signet ring cell carcinoma or mucinous adenocarcinoma was defined as nonadenocarcinoma. cT4 was defined as serosal invasion, and cT1, cT2, and cT3 were defined as nonserosal invasion.