Table 3.
Univariable analysis of the associated factors of lesions determined accurately or inaccurately in the curative resection of undifferentiated type of early gastric cancer by the extreme gradient boosting classifier.
| Characteristics | First external validation set | Second external validation set | |||||
| Accurately determined by XGBoosta classifier (n=224) | Inaccurately determined by XGBoost classifier (n=51) | P value | Accurately determined by XGBoost classifier (n=114) | Inaccurately determined by XGBoost classifier (n=13) | P value | ||
| Sex, n (%) | .06 |
|
|
.37 | |||
|
|
Male | 128 (57.1) | 37 (73) |
|
70 (61.4) | 10 (77) |
|
|
|
Female | 96 (42.9) | 14 (28) |
|
44 (38.6) | 3 (23) |
|
| Age (years), mean (SD) | 67.3 (12.6) | 70.0 (9.2) | .09 | 63.9 (13.3) | 65.5 (10.4) | .66 | |
| Longitudinal location, n (%) | .22 |
|
|
.33 | |||
|
|
Lower-third | 173 (77.2) | 41 (80) |
|
50 (43.9) | 3 (23) |
|
|
|
Mid-third | 21 (9.4) | 7 (14) |
|
53 (46.5) | 8 (62) |
|
|
|
Upper-third | 30 (13.4) | 3 (6) |
|
11 (9.6) | 2 (15) |
|
| Circular location, n (%) | .38 |
|
|
.29 | |||
|
|
Lesser curvature | 74 (33.0) | 21 (41) |
|
46 (40.4) | 3 (23) |
|
|
|
Greater curvature | 45 (20.1) | 13 (26) |
|
23 (20.2) | 4 (31) |
|
|
|
Posterior wall | 58 (25.9) | 10 (20) |
|
21 (18.4) | 1 (8) |
|
|
|
Anterior wall | 47 (20.9) | 7 (14) |
|
24 (21.1) | 5 (39) |
|
| Endoscopic size of the lesion (cm), mean (SD) | 28.4 (16.4) | 25.5 (14.7) | .25 | 22.2 (12.7) | 17.1 (11.4) | .16 | |
| Morphology, n (%) | .36 |
|
|
.93 | |||
|
|
Elevated (I, IIa, and IIa+IIc) | 78 (34.8) | 23 (45) |
|
25 (21.9) | 3 (23) |
|
|
|
Flat (IIb) | 81 (36.2) | 17 (33) |
|
34 (29.8) | 3 (23) |
|
|
|
Depressed (IIc) | 65 (29) | 11 (22) |
|
55 (48.2) | 7 (54) |
|
| Ulcer, n (%) | .86 |
|
|
.21 | |||
|
|
Present | 52 (23.2) | 11 (22) |
|
13 (11.4) | 3 (23) |
|
|
|
None | 172 (76.8) | 40 (78) |
|
101 (88.6) | 10 (77) |
|
aXGBoost: extreme gradient boosting.