Table 4.
Preoperative vs. pathological N staging in five rectal segments
| N stage | uN0 | uN1 | uN2 | |
|---|---|---|---|---|
| SEG I (1, 3]*, cm |
ypN0 | 37 | 4 | 0 |
| ypN1 | 7 | 4 | 0 | |
| ypN2 | 1 | 1 | 1 | |
| SEG II (3, 6], cm |
ypN0 | 93 | 2 | 0 |
| ypN1 | 8 | 14 | 0 | |
| ypN2 | 1 | 3 | 2 | |
| SEG III (6, 9], cm |
ypN0 | 20 | 3 | 0 |
| ypN1 | 3 | 3 | 0 | |
| ypN2 | 1 | 1 | 1 | |
| SEG IV (9, 12], cm |
ypN0 | 3 | 1 | 0 |
| SEG V (12, 16], cm |
ypN0 | 2 | 1 | 0 |
| ypN1 | 2 | 0 | 0 |
* (a, b] means a value larger than a, but no more than b. Abbreviations: uN, ultrasonographic N stage; ypN, pathological N stage after neoadjuvant therapy; SEG, rectal segment.