Abstract
Background There remains a number of factors thought to be associated with survival in spinal metastatic disease, but evidence of these associations is lacking. In this study, we examined factors associated with survival among patients undergoing surgery for spinal metastatic disease.
Methods We retrospectively examined 104 patients who underwent surgery for spinal metastatic disease at an academic medical center. Of those patients, 33 received local preoperative radiation (PR) and 71 had no PR (NPR). Disease-related variables and surrogate markers of preoperative health were identified, including age, pathology, timing of radiation and chemotherapy, mechanical instability by spine instability neoplastic score, American Society of Anesthesiologists (ASA) classification, Karnofsky performance status (KPS), and body mass index (BMI). We performed survival analyses using a combination of univariate and multivariate Cox proportional hazards models to assess significant predictors of time to death.
Results Local PR (Hazard Ratio [HR] = 1.84, P = 0.034), mechanical instability (HR = 1.11, P = 0.024), and melanoma (HR = 3.60, P = 0.010) were significant predictors of survival on multivariate analysis when controlling for confounders. PR vs NPR cohorts exhibited no statistically significant differences in preoperative age (P = 0.22), KPS (P = 0.29), BMI (P = 0.28), or ASA classification (P = 0.12). NPR patients had more reoperations for postoperative wound complications (11.3% vs 0%, P < 0.001).
Conclusions In this small sample, PR and mechanical instability were significant predictors of postoperative survival, independent of age, BMI, ASA classification, and KPS and in spite of fewer wound complications in the PR group. It is possible that PR was a surrogate of more advanced disease or poor response to systemic therapy, independently portending a worse prognosis. Future studies in larger, more diverse populations are crucial for understanding the relationship between PR and postoperative outcomes to determine the optimal timing for surgical intervention.
Clinical Relevance These findings are clinically relevent as they provide insight into factors associated with survival in metastatic spinal disease.
Level of Evidence 3.
Footnotes
Funding The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests The authors report no conflicts of interest in this work.
Disclosures Comron Saifi reports consulting fees from Nuvasive; support for attending meetings/travel from Nuvasive and Medtronic; and stock/stock options from Vertera LLC, Alphatec, and Huxley Medical. Jang Won Yoon reports consulting fees from Depuy Synthes, Pacira, and Biederman Motech and stock/stock options from Kinesiometrics Inc and Medcyclops LLC. The remaining authors have nothing to disclose.
- This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2023 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.