Table 2.
Association between clinical variables and the disease-free interval (DFI) to bone-only metastases
| DFI | |||
|---|---|---|---|
| Clinical variable | < 13 months | ≥ 13 months | P* |
| Gender | 0.286 | ||
| Male | 111 (96.5) | 147 (93.6) | |
| Female | 4 (3.5) | 10 (6.4) | |
| Age (years) | 0.303 | ||
| < 45 | 55 (47.8) | 85 (54.1) | |
| ≥ 45 | 60 (52.2) | 72 (45.9) | |
| Overall stage | 0.358 | ||
| I+II | 9 (7.8) | 8 (5.1) | |
| III+IVB | 106 (92.2) | 149 (94.9) | |
| T category | 0.015 | ||
| T1-2 | 35 (30.4) | 28 (17.8) | |
| T3-4 | 80 (69.6) | 129 (28.2) | |
| N category | 0.042 | ||
| N0-1 | 27 (23.5) | 54 (34.4) | |
| N2-3 | 88 (76.5) | 103 (65.6) | |
| Radiotherapy technique | 0.104 | ||
| 2DRT/3DCRT | 29 (25.2) | 54 (34.4) | |
| IMRT | 86 (74.8) | 103 (65.6) | |
| Primary treatment | 0.164 | ||
| Radiotherapy | 35 (30.4) | 36 (22.9) | |
| Chemoradiotherapy | 80 (69.6) | 121(77.1) | |
| Pretreatment ALP (U/L) | 0.046 | ||
| < 110 | 102 (88.7) | 148 (94.3) | |
| ≥ 110 | 13 (11.3) | 9 (5.7) | |
| Pretreatment EBV DNA (copies ml-1) | 0.029 | ||
| < 6,750 | 52 (45.2) | 92 (58.6) | |
| ≥ 6,750 | 63 (54.8) | 65 (41.4) | |
Abbreviations: DFI = disease-free interval; 2DRT = two-dimensional radiotherapy; 3DCRT = three-dimensional conformal radiotherapy; IMRT = intensity-modulated radiation therapy; LDH = alkaline phosphatase.
* Chi-square test.