Characteristics of the detected early gastric cancers
| Characteristic of the detected EGC | WLI group | 2G-NBI group | P value (primary WLI vs primary 2G-NBI) | P value (secondary WLI vs secondary 2G-NBI) | ||||||
| Detected by primary WLI (n=50) | Detected by secondary 2G-NBI (n=19) | Detected by primary 2G-NBI (n=59) | Detected by secondary WLI (n=17) | |||||||
| Tumour location*, n (%) | 1 | 0.913 | ||||||||
| Upper third | 12 | (24.0) | 5 | (26.3) | 15 | (25.4) | 6 | (35.3) | ||
| Anterior wall | 3 | 0 | 5 | 1 | ||||||
| Lesser curvature | 2 | 0 | 2 | 1 | ||||||
| Posterior wall | 5 | 3 | 5 | 1 | ||||||
| Greater curvature | 2 | 2 | 3 | 3 | ||||||
| Middle third | 23 | (46.0) | 8 | (42.1) | 26 | (44.1) | 7 | (41.2) | ||
| Anterior wall | 5 | 1 | 6 | 1 | ||||||
| Lesser curvature | 9 | 2 | 7 | 2 | ||||||
| Posterior wall | 6 | 0 | 7 | 1 | ||||||
| Greater curvature | 3 | 5 | 6 | 3 | ||||||
| Lower third | 15 | (30.0) | 6 | (31.6) | 18 | (30.5) | 4 | (23.5) | ||
| Anterior wall | 3 | 2 | 0 | 0 | ||||||
| Lesser curvature | 5 | 2 | 6 | 1 | ||||||
| Posterior wall | 2 | 1 | 5 | 0 | ||||||
| Greater curvature | 5 | 1 | 7 | 3 | ||||||
| Tumour macroscopic type*, n (%) | 1 | 0.408 | ||||||||
| 0-I | 2 | (4.0) | 0 | (0) | 2 | (3.4) | 0 | (0) | ||
| 0-IIa | 10 | (20.0) | 5 | (26.3) | 12 | (20.3) | 2 | (11.8) | ||
| 0-IIb | 1 | (2.0) | 0 | (0) | 1 | (1.7) | 0 | (0) | ||
| 0-IIc | 37 | (74.0) | 14 | (73.7) | 44 | (74.6) | 15 | (88.2) | ||
| Tumour histological classification* | 0.059 | 0.605 | ||||||||
| High-grade adenoma | 0 | (0) | 0 | (0) | 5 | (8.5) | 0 | (0) | ||
| Well-differentiated tubular AC | 43 | (86.0) | 16 | (84.2) | 41 | (69.5) | 15 | (88.2) | ||
| Moderately differentiated AC | 5 | (10.0) | 3 | (15.8) | 4 | (6.8) | 1 | (5.9) | ||
| Poorly differentiated AC, solid type | 0 | (0) | 0 | (0) | 1 | (1.7) | 1 | (5.9) | ||
| Poorly differentiated AC, non-solid type | 0 | (0) | 0 | (0) | 1 | (1.7) | 0 | (0) | ||
| Signet-ring cell carcinoma | 2 | (4.0) | 0 | (0) | 3 | (5.1) | 0 | (0) | ||
| Others† | 0 | (0) | 0 | (0) | 4 | (6.8) | 0 | (0) | ||
| Resected EGC, n (%) | 47 | (94.0) | 19 | (100) | 51 | (86.4) | 16 | (94.1) | ||
| Tumour size‡, mm | 11.9±8.9 | 13.3±8.4 | 14.5±9.8 | 12.5±7.5 | 0.183 | 0.766 | ||||
| Tumour depth§, n (%) | 0.777 | 1 | ||||||||
| Mucosa | 41 | (87.2) | 17 | (89.5) | 43 | (84.3) | 15 | (93.8) | ||
| Submucosa | 6 | (12.8) | 2 | (10.5) | 8 | (15.7) | 1 | (6.3) | ||
*Tumour location, macroscopic type and histological classification were classified according to the Japanese Classification of Gastric Carcinoma.14
†Others included a squamous cell carcinoma, a carcinoid tumour, an endocrine carcinoma and a carcinoma with lymphoid stroma.
‡Tumour size was analysed in the resected EGCs. Values are expressed as means±SD.
§Tumour depth was analysed in the resected EGCs.
WLI, white light imaging; 2G-NBI, second-generation narrow band imaging; EGC, early gastric cancer; AC, adenocarcinoma.