Table 3.
Univariate and multivariate analyses for LRFS, MMFS, PFS, and OS (n = 84).
| Risk Factor | LRFS | MMFS | PFS | OS | ||||
|---|---|---|---|---|---|---|---|---|
| HR | p | HR | p | HR | p | HR | p | |
| Univariate model | ||||||||
| Age (years) | 1.06 | 0.09 | 1.005 | 0.8 | 1.034 | 0.06 | 1.085 | 0.08 |
| EMP vs. SBP | 1.26 | 0.7 | 0.602 | 0.3 | 0.82 | 0.6 | 2.85 | 0.3 |
| Diameter (cm) | 0.89 | 0.7 | 1.17 | 0.3 | 1.06 | 0.6 | 1.74 | 0.07 |
| Bone erosion | 4.24 | 0.15 | 0.302 | 0.26 | 0.99 | 0.9 | 0.71 | 0.8 |
| Surgical resection | 2.29 | 0.26 | 0.67 | 0.5 | 0.91 | 0.8 | 0.49 | 0.4 |
| RT dose (>40 Gy vs. ≤40 Gy) | 0.38 | 0.2 | 1.39 | 0.5 | 1.12 | 0.7 | 1.92 | 0.5 |
| Modern RT technique | 0.83 | 0.02 | 2.08 | 0.4 | 0.72 | 0.5 | 1.06 | 0.9 |
| CR after RT | 1.39 | 0.6 | 0.42 | 0.09 | 0.67 | 0.3 | 1.01 | 0.9 |
| B2-microglobulin (normal) | 6.0 | 0.2 | 3.22 | 0.1 | 0.31 | 0.08 | 0.285 | 0.3 |
| Serum protein (normal) | 0.024 | 0.002 | 0.94 | 0.9 | 0.24 | 0.02 | 28.1 | 0.7 |
| Hemoglobin (g/dl) | 1.32 | 0.5 | 0.67 | 0.006 | 0.68 | 0.004 | 0.91 | 0.7 |
| Systemic therapy | 1.09 | 0.9 | 0.44 | 0.19 | 0.47 | 0.1 | 0.03 | 0.5 |
| Multivariate model | ||||||||
| Age (years) | - | - | - | - | - | - | 1.14 | 0.1 |
| Diameter | - | - | - | - | - | - | 2.29 | 0.03 |
| Modern RT technique | 0.036 | 0.012 | - | - | - | - | - | - |
| Serum protein (normal) | 0.019 | 0.008 | - | - | - | - | - | - |
| Hemoglobin (g/dl) | - | - | 0.676 | 0.006 | 0.655 | 0.004 | ||
LRFS, local relapse-free survival; MMFS, multiple myeloma-free survival; PFS, progression-free survival; OS, overall survival; HR, hazard ratio; EMP, solitary extramedullary plasmacytoma; SBP, solitary bone plasmacytoma; RT, radiotherapy; IMRT; intensity modulated radiotherapy; CR, complete remission.