Table 2.
Comparison of basic characteristics between patients who underwent postoperative radiotherapy [PORT (+)] and those who did not undergo postoperative radiotherapy [PORT (−)]
| PORT (+) | PORT (−) | P value | |||
|---|---|---|---|---|---|
| No | % | No | % | ||
| Sex | |||||
| Male | 57 | 46.0 | 24 | 38.1 | 0.304 |
| Female | 67 | 54.0 | 39 | 61.9 | |
| Location | |||||
| Parotid | 17 | 13.7 | 12 | 19.0 | 0.268 |
| Submandibular | 24 | 19.4 | 13 | 20.6 | |
| Sublingual | 8 | 6.5 | 8 | 12.7 | |
| Minor salivary gland | 75 | 60.5 | 30 | 47.6 | |
| Histologic grade | |||||
| Grade 1 | 43 | 34.7 | 27 | 42.9 | 0.395 |
| Grade 2 | 54 | 43.5 | 22 | 34.9 | |
| Grade 3 | 13 | 10.5 | 4 | 6.3 | |
| Unknown | 14 | 11.3 | 10 | 15.9 | |
| T stage | |||||
| T1 | 1 | 0.8 | 0 | 0.0 | < 0.001 |
| T2 | 20 | 16.1 | 32 | 50.8 | |
| T3 | 42 | 33.9 | 20 | 31.7 | |
| T4 | 27 | 21.8 | 5 | 7.9 | |
| N stage | |||||
| N0 | 110 | 88.7 | 63 | 100.0 | 0.021 |
| N1 | 6 | 4.8 | 0 | 0.0 | |
| N2 | 8 | 6.5 | 0 | 0.0 | |
| Lymph node dissection | |||||
| Not performed | 90 | 72.6 | 41 | 65.1 | 0.290 |
| Performed | 34 | 27.4 | 22 | 34.9 | |
| Surgical margin | |||||
| Positive | 86 | 69.4 | 18 | 28.6 | < 0.001 |
| Close | 29 | 23.4 | 28 | 44.4 | |
| Negative | 9 | 7.3 | 17 | 27.0 | |
| Positive margin | |||||
| No | 38 | 30.6 | 45 | 71.4 | < 0.001 |
| Yes | 86 | 69.4 | 18 | 28.6 | |
| PNI | |||||
| No | 52 | 41.9 | 43 | 68.3 | 0.001 |
| Yes | 72 | 58.1 | 20 | 31.7 | |
| LVI | |||||
| No | 98 | 79.0 | 58 | 92.1 | 0.024 |
| Yes | 26 | 21.0 | 5 | 7.9 | |
| Nerve invasion | |||||
| No | 113 | 91.1 | 60 | 95.2 | 0.313 |
| Yes | 11 | 8.9 | 3 | 4.8 | |
| Bone invasion | |||||
| No | 90 | 72.6 | 56 | 88.9 | 0.011 |
| Yes | 34 | 27.4 | 7 | 11.1 | |
PORT postoperative radiotherapy, PNI perineural invasion, LVI lymphovascular invasion