Preoperative Predictors of Survival in Patients With Spinal Metastatic Disease

Stephen P Miranda; Patricia Zadnik Sullivan; Ahmed Albayar; Ashwin G Ramayya; Rachel Blue; Zarina S Ali; Neil Malhotra; Paul Marcotte; Jang Yoon; Comron Saifi; William C Welch; James Schuster; Ali K Ozturk

doi:10.14444/8444

Preoperative Predictors of Survival in Patients With Spinal Metastatic Disease

Int J Spine Surg. 2023 Aug;17(4):557-563. doi: 10.14444/8444. Epub 2023 Mar 8.

Affiliations

¹ Department of Neurosurgery, Hospital of University of Pennsylvania, Philadelphia, PA, USA.
² Department of Neurosurgery, Hospital of University of Pennsylvania, Philadelphia, PA, USA Rachel.Blue@pennmedicine.upenn.edu.
³ Department of Neurosurgery, Pennsylvania Hospital, University of Pennsylvania, Philadelphia, PA, USA.
⁴ Department of Orthopedic Surgery, Pennsylvania Hospital, University of Pennsylvania, Philadelphia, PA, USA.
⁵ Department of Neurosurgery, Penn Presbyterian Hospital, University of Pennsylvania, Philadelphia, PA, USA.

PMID: 36889904
PMCID: PMC10478689
DOI: 10.14444/8444

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.

Keywords: mortality risk; preoperative spinal radiation; radiation therapy; spinal instability; spinal metastasis.

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.