Table 2 Comparison of basic characteristics between patients who underwent postoperative radiotherapy [PORT (+)] and those who did not undergo postoperative radiotherapy [PORT (−)]
From: Role of postoperative radiotherapy in resected adenoid cystic carcinoma of the head and neck
|  | 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 |  |