Table 3 Tumor characteristics
|  | LN− group n = 167 (%) | LN+ group n = 980 (%) | p value |
|---|---|---|---|
Tumor location | |||
 Right side colon | 34 (20.4) | 284 (29) | 0.066 |
 Left side colon | 71 (42.5) | 360 (36.7) | |
 Rectum | 62 (37.1) | 336 (34.3) | |
Circumferential involvement | |||
 Yes | 122 (73.1) | 734 (74.9) | 0.631 |
 No | 45 (26.9) | 246 (25.1) | |
Associated polyps | |||
 Yes | 61 (36.5) | 394 (40.2) | 0.369 |
 No | 106 (63.5) | 586 (59.8) | |
Tumor diameter (cm) | |||
 < 5cm | 82 (49.1) | 437 (44.6) | 0.313 |
 ≥ 5cm | 85 (50.9) | 543 (55.4) | |
Depth of tumor invasion | |||
 T4 | 62 (37.1) | 472 (48.2) | 0.008 |
 Non-T4 | 105 (62.9) | 508 (51.8) | |
Examined LN number | 25 [16–39]* | 28 [19–39]* | 0.038 |
Total positive LN number | 0 [0–0]* | 6 [3–11]* | <0.001 |
Local tumor clearance | |||
 R0 | 59 (35.3) | 283 (28.9) | 0.092 |
 Non-R0 | 108 (64.7) | 697 (71.1) | |
Histologic type | |||
 Adenocarcinoma | 155 (92.8) | 873 (89.1) | 0.121 |
 Signet ring cell adenocarcinoma | 1 (0.6) | 34 (3.5) | |
 Mucinous adenocarcinoma | 11 (6.6) | 73 (7.4%) | |
Histologic gradea | |||
 Well or moderately differentiated | 155 (92.8) | 789 (80.8) | <0.001 |
 Poorly differentiated | 12 (7.2) | 188 (19.2) | |
Desmoplastic reactiona | |||
 Mild | 41 (24.6) | 209 (21.3) | 0.331 |
 Moderate | 106 (63.5) | 613 (61.6) |  |
 Marked | 20 (12) | 157 (16) |  |
Tumor necrosisa | |||
 Mild | 72 (49.7) | 414 (47) | 0.824 |
 Moderate | 53 (36.6) | 344 (39.1) | |
 Marked | 20 (13.8) | 122 (13.9) | |
Lymphovascular invasiona | |||
 Yes | 39 (23.4) | 755 (77.4) | <0.001 |
 No | 128 (76.6) | 221 (22.6) | |
Perineural invasiona | |||
 Yes | 58 (34.7) | 581 (59.7) | <0.001 |
 No | 109 (65.3) | 393 (40.3) | |