Table 2. Macroscopic and histopathologic characteristics of early gastric cancer lesions (n=5,454).
| Variable | Overall | |
|---|---|---|
| Endoscopic tumor size (cm) | 1.9±1.0 | |
| Location | ||
| Upper third | 565 (10.4) | |
| Middle third | 1,396 (25.6) | |
| Lower third | 3,489 (64.0) | |
| Remnant stomach | 4 (0.1) | |
| Macroscopic type | ||
| I | 110 (2.0) | |
| IIa | 1,068 (19.6) | |
| IIb | 1,005 (18.4) | |
| IIc | 1,966 (36.0) | |
| III | 22 (0.4) | |
| Mixed type* | 1,283 (23.5) | |
| Pathologic tumor size (cm) | 1.7±1.1 | |
| Histology | ||
| Papillary adenocarcinoma | 39 (0.7) | |
| Tubular adenocarcinoma (WD) | 2,833 (51.9) | |
| Tubular adenocarcinoma (MD) | 1,914 (35.1) | |
| Tubular adenocarcinoma (PD) | 207 (3.8) | |
| PCC and/or SRC | 381 (7.0) | |
| Other rare histologic types | 80 (1.5) | |
| Depth of invasion | ||
| Lamina propria | 2,649 (48.6) | |
| Muscularis mucosa | 1,897 (34.8) | |
| Superficial submucosa (≤500 μm)† | 436 (8.0) | |
| Deep submucosa (>500 μm) | 472 (8.7) | |
| Lymphovascular invasion | ||
| Absent | 5,079 (93.1) | |
| Present | 375 (6.9) | |
Values are shown as the mean ± standard deviation or number (%). Data are presented on a lesion basis. Patients with multiple gastric lesions were included in the analysis more than once. Six lesions in which endoscopic submucosal dissection was discontinued due to technical difficulty or procedure-related complications (non-lifting, n=4; uncontrolled bleeding, n=1; suspected perforation, n=1) were excluded from this table. All of these 6 lesions subsequently underwent surgical management. These cases were included in the analysis of procedure-related adverse events but excluded from lesion-based curability analyses. Tumor size represents the maximum diameter (long axis) measured during endoscopy or on the resected specimen.
WD = well-differentiated; MD = moderately differentiated; PD = poorly differentiated; PCC = poorly cohesive carcinoma; SRC = signet ring cell carcinoma.
*Mixed type indicates lesions with multiple macroscopic features (e.g., IIa+IIc, IIb+IIc).
†Submucosal invasion depth was measured from the muscularis mucosa to the deepest point of tumor invasion (cutoff: ≤500 μm, Korean guidelines).