Table 2.
Univariate analysis for survival of patients
| Feature | Cases | Median survival (mo) | 5-yr OS | χ2 value | P value | |
| Gender | Male | 120 | 19.2 | 24.2% | 0.896 | 0.344 |
| Female | 33 | 24.3 | 34.6% | |||
| Age (yr) | ≤ 60 | 77 | 22.1 | 29.5% | 1.159 | 0.282 |
| > 60 | 76 | 20 | 23.2% | |||
| Lesion location | Neck, upper thorax | 73 | 23.4 | 38.8% | 6.497 | 0.011 |
| Middle, lower thorax | 80 | 18.5 | 13.5% | |||
| LCAH | No | 137 | 19.2 | 26.7% | 0.257 | 0.612 |
| Yes | 16 | 30.4 | 25% | |||
| RT dose (Gy) | ≤ 64 | 86 | 19.4 | 23.8% | 0.429 | 0.512 |
| > 64 | 67 | 22.4 | 29.7% | |||
| Chemotherapy | No | 99 | 18.4 | 26.5% | 0.438 | 0.508 |
| Yes | 54 | 23.4 | 25.5% | |||
| The length of lesion in barium esophagogram (cm) | ≤ 3 | 12 | - | 80.8% | 13.627 | 0.003 |
| > 3, ≤ 5 | 57 | 22.4 | 23.8% | |||
| > 5, ≤ 7 | 52 | 16.8 | 20.9% | |||
| > 7 | 32 | 17.8 | 21.7% | |||
| Largest diameter (cm) | ≤ 2 | 11 | - | 72.7% | 12.729 | 0.002 |
| > 2, ≤ 3 | 43 | 23.4 | 33.7% | |||
| > 3 | 99 | 17.3 | 17.3% | |||
| Y diameter (cm) | ≤ 2 | 29 | - | 60.3% | 11.574 | 0.001 |
| > 2 | 124 | 18.4 | 18.3% | |||
| X diameter (cm) | ≤ 2 | 16 | - | 62.5% | 15.319 | 0.006 |
| > 2, ≤ 3 | 49 | 22.1 | 31.7% | |||
| > 3, ≤ 4 | 59 | 18.1 | 23% | |||
| > 4 | 29 | 17.8 | 0% | |||
| Thickness of esophageal wall (cm) | ≤ 1 | 32 | 34.8 | 46.2% | 8.224 | 0.016 |
| > 1, ≤ 2 | 104 | 18.4 | 22.0% | |||
| > 2 | 17 | 17.2 | 12.8% | |||
| Length of lesion (cm) | < 4 | 10 | - | 57.1% | 7.462 | 0.024 |
| ≥ 4, ≤ 9 | 126 | 20 | 26% | |||
| > 9 | 17 | 13.9 | 9.2% | |||
| GTV-E (cm3) | < 18 | 40 | 37.8 | 42.9% | 9.934 | 0.007 |
| ≥ 18, ≤ 48 | 82 | 18.4 | 24.6% | |||
| > 48 | 31 | 14.5 | 8.6% | |||
| Invasion to adjacent structure | No | 65 | 24.3 | 38.1% | 7.289 | 0.007 |
| Yes | 88 | 17.7 | 17.8% | |||
| Invasion to trachea | No | 96 | 22.5 | 27.5% | 0.865 | 0.352 |
| Yes | 57 | 17.8 | 24.5% | |||
| Invasion to bronchus | No | 131 | 22.1 | 29.9% | 3.992 | 0.046 |
| Yes | 22 | 15.8 | 5.6% | |||
| Invasion to aorta | No | 128 | 22.1 | 29% | 1.469 | 0.226 |
| Yes | 25 | 17.8 | 13.9% | |||
| Invasion to pericardia | No | 145 | 20 | 27.9% | 1.559 | 0.212 |
| Yes | 8 | 16.9 | 0% | |||
| SLNM1 | Yes | 25 | 15.9 | 21.1% | 1.317 | 0.251 |
| No | 107 | 22.4 | 23.6% | |||
| Number of positive lymph nodes2 | 0 | 55 | 30.4 | 38.4% | 9.709 | 0.008 |
| 1-2 | 85 | 18.4 | 21.2% | |||
| > 2 | 13 | 13.8 | 7.7% | |||
| GTV-LN (cm3) | 0 | 55 | 30.4 | 38.4% | 9.229 | 0.010 |
| 0-3 | 59 | 19.2 | 22.8% | |||
| > 3 | 39 | 15.9 | 14% | |||
| GTV-T (cm3) | < 20 | 41 | 39.8 | 41.5% | 12.891 | 0.002 |
| 20-40 | 64 | 18.1 | 28.6% | |||
| > 40 | 48 | 15.4 | 9.2% |
1
SLNM: Supraclavicular lymph node metastasis, only the thoracic cases were included;
2
N0: No positive lymph node was observed. N+: Peri-esophageal lymph node with longest diameter of ≥ 5 mm, mediastinal lymph nodes or supraclavicular lymph nodes with shortest diameter of ≥ 10 mm. LCAH: Late course accelerated hyperfractionated radiotherapy; OS: Overall survival; GTV-E: Gross tumor volume of primary lesion; GTV-LN: Volume of positive lymph nodes; GTV-T: Total gross tumor volume.