Table 3.
Analysis of Prognostic Factors for Overall Survival
| Variables | 3-year overall survival (%) | P-value | |
|---|---|---|---|
| Univariate | Multivariate | ||
| RT technique | |||
| IMRT vs. 3D-CRT | 87.5 vs. 76.0 | 0.391 | 0.244 |
| Age (years) | |||
| <50 vs. ≥50 | 72.7 vs. 94.1 | 0.186 | 0.178 |
| Gender | |||
| Male vs. female | 81.6 vs. 85.7 | 0.875 | |
| Smoking status | |||
| Current or previous vs. never | 79.7 vs. 88.9 | 0.611 | |
| Alcohol status | |||
| Current or previous vs. never | 80.4 vs. 87.5 | 0.759 | |
| WHO histologya | |||
| 1 vs. 2-3 | 82.5 vs. 82.7 | 0.974 | |
| T stage | |||
| 1-2 vs. 3-4 | 93.3 vs. 70.0 | 0.147 | 0.126 |
| N stage | |||
| 0-1 vs. 2-3 | 85.7 vs. 81.2 | 0.816 | |
| AJCC stage | |||
| 3 vs. 4 | 90.7 vs. 59.3 | 0.074 | 0.070 |
| GTV (cc) | |||
| ≤55 vs. >55 | 92.9 vs. 73.9 | 0.253 | 0.571 |
| Total RT dose (BED, Gy10) | |||
| ≤82.5 vs. >82.5 | 67.6 vs. 100 | 0.026 | 0.255 |
| Daily dose (Gy) | |||
| ≤2 vs. >2 | 86.1 vs. 72.9 | 0.467 | 0.443 |
| RT duration (weeks) | |||
| ≤7.5 vs. >7.5 | 92.9 vs. 73.7 | 0.209 | 0.327 |
| RT interruption | |||
| Yes vs. no | 64.2 vs. 94.4 | 0.046 | 0.075 |
| Induction chemotherapy | |||
| Yes vs. no | 79.4 vs. 85.7 | 0.522 | |
RT, radiotherapy; IMRT, intensity-modulated radiotherapy; 3D-CRT, 3-dimensional conformal radiotherapy; WHO, World Health Organization; AJCC, American Joint Committee on Cancer Staging; GTV, gross tumor volume; BED, biologically equivalent dose.
a
WHO histology I, keratinizing squamous cell carcinoma; II, non-keratinizing carcinoma, differentiated type; III, non-keratinizing carcinoma, undifferentiated type