Preoperative predictors of time to death in patients with spinal metastatic disease.
| Radiation Status | No PR | PR |
| Number of cases (% of total) | 71 (68.3%) | 33 (31.7%) |
| Age, y, mean (range) | 59.9 (87.3–35.8) | 63 (31.6–85.7) |
| Body mass index, mean (range) | 27.6 (16.8–42.9) | 26.2 (16–37.8) |
| Surgical complications (infection, wound hematoma, and dehiscence), n (%) | 8 (11.3%) | 0 |
| Deaths, n (%) | 31 (44%) | 24 (73%) |
| Time to death, d, mean (range) | 178.5 (2–897) | 218.5 (3–889) |
| Hazard ratio | 1.84 | |
| P value | 0.034 |
| SINS | Stable (<13) | Unstable (≥13) |
| Number of cases (% of total) | 70 (67%) | 34 (33%) |
| Deaths, n (%) | 32 (46%) | 23 (94%) |
| Time to death, d, mean (range) | 219.7 (14–889) | 162.9 (2–897) |
| Hazard ratio | 1.11 | |
| P value | 0.024 |
| Melanoma | Total |
| Number of cases (% of total) | 5 (4.8%) |
| Deaths, n (%) | 5 (100%) |
| Time to death, d, mean (range) | 194.5 (24–218) |
| Hazard ratio | 3.6 |
| P value | 0.010 |
Note: We performed multivariate survival analysis using Cox proportional hazards model while accounting for the following variables, which demonstrated significance on univariate analysis (P < 0.05): SINS score, local radiation before surgery, presence of liver metastasis, primary melanoma, and primary genitourinary cancer.
PR, preoperative radiation; SINS, spine instability neoplastic score.