Table 3.
Risk factors associated with lymph node metastasis for rectal NET.
| G1 n = 515 | G2 n = 86 | G1+G2 n = 601 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| metastasis | no | yes | %* | no | yes | % | no | yes | % |
| Tumor size (cm) | p = 3.7E-31 | p = 2.4E-5 | p = 9.8E-47 | ||||||
| <1 | 380 | 2 | 0.5 | 17 | 0 | 0 | 397 | 2 | 0.5 |
| 1-2 | 99 | 13 | 11.6 | 21 | 16 | 43.2 | 120 | 29 | 19.5 |
| >2 | 9 | 12 | 57.1 | 10 | 22 | 68.8 | 19 | 34 | 64.1 |
| Invading depth** | p = 2.9E-46 | p = 2.0E-6 | p = 7.8E-63 | ||||||
| T0-1 | 470 | 7 | 1.4 | 32 | 4 | 11.1 | 502 | 11 | 2.1 |
| T2 | 14 | 8 | 36.4 | 5 | 7 | 58.3 | 19 | 15 | 44.1 |
| T3 | 2 | 4 | 66.7 | 6 | 19 | 76.0 | 8 | 23 | 74.2 |
| T4 | 2 | 8 | 80.0 | 4 | 7 | 63.6 | 6 | 15 | 71.4 |
| MVI | p = 0.030 | p = 0.042 | p = 1.8E-5 | ||||||
| no | 226 | 18 | 7.4 | 28 | 21 | 42.9 | 254 | 39 | 13.3 |
| yes | 6 | 3 | 33.3 | 2 | 8 | 80.0 | 8 | 11 | 57.9 |
| PNI | p = 0.359 | p = 1.3E-4 | p = 7.7E-9 | ||||||
| no | 224 | 20 | 8.2 | 29 | 15 | 34.1 | 253 | 35 | 12.1 |
| yes | 4 | 1 | 20.0 | 1 | 13 | 92.9 | 5 | 14 | 73.7 |
| Size and depth | p = 5.7E-41 | p = 4.2E-7 | p = 1.4E-60 | ||||||
| <1cm and T1 | 376 | 1 | 0.3 | 17 | 0 | 0 | 393 | 1 | 0.3 |
| 1-2cm and T1 | 93 | 6 | 6.1 | 15 | 4 | 21.1 | 108 | 10 | 8.5 |
| >2cm or T2 | 19 | 20 | 51.3 | 15 | 33 | 68.8 | 34 | 53 | 60.9 |
| 1-2cm and T1 subgroup*** | p = 0.546 | p = 0.014 | p = 0.014 | ||||||
| MVI/PNI - | 49 | 10 | 16.9 | 12 | 4 | 25.0 | 61 | 14 | 18.7 |
| MVI/PNI + | 3 | 1 | 25.0 | 0 | 4 | 100 | 3 | 5 | 62.5 |
MVI, Micro-Vascular Invasion; PNI, Peri-Neural Invasion.
Chi-square analysis was used.
*% = yes/(yes + no).
**T stage only indicates tumor invading depth, without consideration of tumor size.
***One hundred-eighteen cases were with tumors sized 1-2 cm in diameter and confined to submucosa, of which 83 cases were with complete information of MVI and PNI for analysis.