Table 1. Clinicopathological characteristics of resected colorectal neoplasms.
| Total | Trainee A | Trainee B | |||||
| First period | Latter period | P value | First period | Latter period | P value | ||
| Number of lesions | 80 | 20 | 20 | 20 | 20 | ||
| Tumor size, mm | 32 ± 12 | 30 ± 11 | 33 ± 14 | 0.41 | 43 ± 15 | 39 ± 11 | 0.32 |
| Macroscopic type | |||||||
| LST-G | 49 | 8 | 12 | 11 | 18 | ||
| LST-NG | 25 | 10 | 8 | 6 | 1 | ||
| Protruded | 6 | 2 | 0 | 3 | 1 | ||
| Location of the lesions | 0.34 | 0.70 | |||||
| Colon | 67 | 16 | 19 | 15 | 17 | ||
| Rectum | 13 | 4 | 1 | 5 | 3 | ||
| Fibrosis | 19 | 2 | 11 | 0.006 | 5 | 1 | 0.18 |
| Large nodule | 16 | 3 | 3 | 0.99 | 7 | 3 | 0.27 |
| Central depression | 9 | 0 | 7 | 0.008 | 2 | 0 | 0.49 |
| Pathological characteristics | |||||||
| Adenocarcinoma | 25 | 6 | 6 | 0.99 | 9 | 4 | 0.11 |
| Lymph and/or vascular invasion | 4 | 2 | 0 | 0.24 | 2 | 0 | 0.24 |
| Submucosal invasion | 15 | 3 | 4 | 0.99 | 7 | 1 | 0.04 |
LST-G, laterally spreading tumor, granular type; LST-NG, laterally spreading tumor, nongranular type.Continuous data are shown as the mean ± SD. P values were analyzed using the Fisher exact test, or the Student’s t test for tumor size.