Table 1 Univariate analysis of risk factors and occurrence of lymph node metastasis
Factors | N | LNM(−),n(%) | LNM(+),n(%) | P-value |
|---|---|---|---|---|
N | 288 | 271 | 17 | Â |
Gender | Â | Â | Â | 0.431 |
 Male | 162 | 154 (53.47) | 8 (47.06) |  |
 Female | 126 | 117 (46.53) | 9 (52.94) |  |
Age,χ ± SD (years old) | 59.5 + 11.6 | 59.7 + 11.7 | 56.8 + 11.2 | 0.316 |
Smoking | Â | Â | Â | 0.084 |
 Positive | 68 | 67 (23.26) | 1 (5.88) |  |
 Negative | 220 | 204 (76.74) | 16 (94.12) |  |
Alcohol | Â | Â | Â | 0.520 |
 Positive | 43 | 41 (15.13) | 2 (11.76) |  |
 Negative | 245 | 230 (84.87) | 15 (88.24) |  |
Family history | Â | Â | Â | 0.557 |
 Positive | 10 | 10 (3.69) | (0.00) |  |
 Negative | 278 | 261 (96.31) | 17 (100.00) |  |
Tumor size, χ ± SD (mm) | 30.0 ± 15.6 | 29.2 ± 15.4 | 38.3 ± 17.3 | 0.026* |
Tumor location | Â | Â | Â | 0.115 |
 Rectum | 186 | 171 (63.10) | 15 (88.24) |  |
 Sigmoid colon | 68 | 68 (25.09) | 0 |  |
 Ascending colon | 19 | 17 (6.27) | 2 (11.76) |  |
 Descending colon | 10 | 10 (3.69) | 0 |  |
 Transverse colon | 5 | 5 (1.85) | 0 |  |
Endoscopic morphology | Â | Â | Â | 0.703 |
 I (the uplift type) | 248 | 232 (85.61) | 16 (94.12) |  |
 II (the flat type) | 7 | 7 (2.58) | 0 (0.00) |  |
 III (the concave type) | 25 | 24 (8.86) | 1 (5.88) |  |
 Uncertain | 8 | 8 (2.95) | 0 (0.00) |  |
Pathology |  |  |  | < 0.001** |
 Highly differentiated | 78 | 78 (28.78) | 0 (0.00) |  |
 Moderately differentiated | 202 | 189 (69.74) | 13 (76.47) |  |
 Poorly differentiated | 8 | 4 (1.48) | 4 (23.53) |  |
Depth of invasion | Â | Â | Â | 0.255 |
 Mucosal layer | 76 | 74 (27.31) | 2 (11.76) |  |
 Submucosal layer | 212 | 197 (72.69) | 15 (88.24) |  |
Lympho-vascular invasion |  |  |  | < 0.001** |
 Positive | 6 | 2 (0.74) | 4 (23.53) |  |
 Negative | 282 | 269 (99.26) | 13 (76.47) |  |
Tumor budding | Â | Â | Â | 0.833 |
 Positive | 3 | 3 (1.11) | 0 (0.00) |  |
 Negative | 285 | 268 (98.89) | 17 (100.00) |  |