Table 2 The relationship between postoperative radiotherapy and observation groups in 5-year overall and disease-free survivals among different quality of neck dissection, n = 1765
LNs < 18 | 18 ≦ LNs < 25 | 25 ≦ LNs | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Total | Event (%) | Survival rate (%) | P value | Total | Event (%) | Survival rate (%) | P value | Total | Event (%) | Survival rate (%) | P value | |
Overall survival | 598 | 215 (36.0) | 60.7 | < 0.001 | 289 | 88 (30.5) | 65.1 | 0.025 | 878 | 263 (30.0) | 64.1 | 0.848 |
Without RT | 244 | 111 (45.5) | 50.4 | 105 | 40 (38.1) | 56.4 | 349 | 103 (29.5) | 65.1 | |||
With RT | 354 | 104 (29.4) | 67.8 | 184 | 48 (26.1) | 70.0 | 529 | 160 (30.3) | 63.4 | |||
Disease-specific survival | 598 | 109 (18.2) | 78.0 | 0.003 | 289 | 47 (16.3) | 80.6 | 0.559 | 878 | 164 (16.7) | 76.7 | 0.199 |
Without RT | 244 | 56 (23.0) | 71.7 | 105 | 18 (17.1) | 78.5 | 349 | 57 (16.3) | 79.5 | |||
With RT | 354 | 53 (15.0) | 82.1 | 184 | 29 (15.8) | 81.8 | 529 | 107 (20.2) | 74.8 | |||