Surgical Decisions

New score aims to predict spinal metastases outcomes

Mark Crawford, OREF contributing writer

Nearly one-third of patients with malignancies will develop metastases to the spine. Making surgical determinations within this patient group can be a tough challenge, especially when life expectancy and long-term quality of life cannot be accurately predicted. Because negative impacts of post-surgical morbidity on survival and remaining quality of life often occur, operative treatments may not be the best choice for some patients.

A number of variables play into this important decision-making process. To date there is no scoring system that enables surgeons to accurately forecast outcomes for individuals following surgical intervention; data is even more scarce regarding the impact of non-operative treatments.

Many of the prognostic grading scales and scoring systems for spinal metastases used by the surgical spine community, including the Tokuhashi and Tomita scales, are intended to guide surgical decision-making rather than accurately predict postoperative survival.^{1, 2} Other popular systems, such as the Bauer score and Karnofsky performance status, are not specific to patients with spinal metastases.^{3, 4} Therefore the predictive capacity, reliability, and reproducibility of these classification systems for patients with spinal metastases are limited.

These shortcomings highlight the need for a validated, comprehensive scoring system for this patient population.

To address this need, Andrew J. Schoenfeld, MD, MSc assistant professor of spine surgery at Brigham and Women’s Hospital in Boston, with the help of a 2017 OREF Prospective Clinical Research Grant, is developing a scoring system that can assess long-term postoperative survival and accurately predict peri-operative results. His study, titled “Validation of a Novel Predictive Score for Patients with Spinal Metastases,” intends to develop and validate a clinical score that accurately predicts survival, post-treatment morbidity, and functional outcomes for patients being treated for metastatic spinal disease.

“The advances in spine surgery and oncology have increased survival for patients with spinal metastases who we would have previously anticipated to live only a few months. But living longer presents a unique set of challenges because for any individual patient we need to weigh their investment in terms of the time it’s going to take to recover from surgery and the potential for adverse events against the likelihood of advanced clinical deterioration in the near term,” Dr. Schoenfeld explained. "The scoring system we develop will help surgeons inform patients to aid them in making a decision about whether surgical intervention is right for them. They'll have a better idea of what to expect because they'll be able to see what the experience of patients with similar scores has been."

An innovative scoring system

The risks of surgical intervention for patients with spinal metastases must be weighed against the potential for meaningful clinical improvement, as well as survival. Dr. Schoenfeld hopes to develop a prognostic scoring system that uses a patient’s modified Bauer score, preoperative serum albumin, and ambulatory status to predict survival.

This research has three main goals:

Goal 1: Evaluate the ability of the prognostic score to accurately predict survival, morbidity, and functional outcomes in patients with metastatic disease involving the spine.

Participants will receive a predictive score based on their modified Bauer score, pre-operative ambulatory status, and serum albumin. They will be monitored, regardless of choice of treatment (surgical, non-operative radiation/chemotherapy, or expectant management) for the development of disease-related morbidity, treatment-related complications, functional outcomes, and survival.

Goal 2: Determine the impact of the predictive score on estimations of survival, post-treatment morbidity, and functional outcomes among patients treated with surgery, as compared to those managed non-operatively.

Patients who received surgery will be compared to those managed non-operatively using propensity-matched techniques. The propensity score will be developed based on clinical characteristics that drive decisions for surgical intervention, such as cancer diagnosis and medical co-morbidities. The capacity of the predictive score to inform outcomes in the setting of surgical or non-operative intervention will then be evaluated.

Goal 3: Compare the accuracy of the predictive score to other accepted grading schemes for patients with spinal metastases in prognosticating outcomes following surgical intervention.

Performance of the predictive score with respect to survival, post-operative morbidity, and functional outcomes will be compared to that of other popular scoring systems, including the Tokuhashi scale and modified Bauer score. The discriminative capacity of each system with respect to the outcomes of interest will be assessed. Performance of each scoring system will be evaluated in unadjusted and adjusted models.

“To the best of our knowledge,” said Dr. Schoenfeld, “this is the first prospective application of multiple prognostic scores to patients with spinal metastatic disease and the first study to determine the ability of these scores to predict functional outcomes, as well as survival and post-treatment morbidity. Use of propensity score matching to evaluate the potential for the score to successfully inform surgical decisions is also a novel approach to the study of patients with metastatic spinal disease.”

The first journal article resulting from the OREF-funded work was published in the November 2019 issue of The Spine Journal⁵. In it, Dr. Schoenfeld and his team described the design of their study.

First phase under way

Patients for the study were enrolled through June 2019. With data collection continuing through June 2020, Dr. Schoenfeld expects preliminary results to be available in early 2020. These will reveal the capability of the predictive score to inform survival, morbidity, and functional outcomes in patients with metastatic spinal disease, regardless of interventions received. He is optimistic his predictive score will perform better than other grading schemes for predicting post-treatment outcomes for patients with metastatic spinal disease—making it of immediate use to these patients as well as to oncologists and surgeons. Dr. Schoenfeld and his research team have completed the investigation associated with aim 1 of the research and submitted a journal article with their findings to The Spine Journal for consideration.

Building on this research, Dr. Schoenfeld plans to design a larger-scale, multi-center prospective observational study, where the prediction score will be used to prognosticate outcomes at several collaborating centers across the U.S. “This will be the final step in determining this score’s capacity to inform the care of patients with metastatic spinal disease,” he said.

Dr. Schoenfeld’s OREF grant enabled the launch of this research project. The funding, for example, financed the tablets used for data collection and patient compliance. “The OREF vision advocates that its research should lead to treatments that improve function, eliminate pain, and restore mobility,” said Dr. Schoenfeld. “Our research study meets all of these guideposts and I am grateful for OREF’s support.”

If his proposed aims are achieved, Dr. Schoenfeld expects his study to provide the best-available evidence regarding anticipated survival, morbidity, and functional outcome, and be especially useful for proposing a plan of care. “This will enable treating physicians and surgeons to confidently inform patients of the inherent risks and benefits of various treatment approaches and facilitate informed decision-making for patients and their families.”

References

1. Tokuhashi Y, Uei H, Oshima M, Ajiro Y. Scoring system for prediction of metastatic spine tumor prognosis. World J Orthop. 2014;5(3):262–271. Published 2014 Jul 18. doi:10.5312/wjo.v5.i3.262

2. Aoude A, Amiot LP. A comparison of the modified Tokuhashi and Tomita scores in determining prognosis for patients afflicted with spinal metastasis. Can J Surg. 2014;57(3):188–193. doi:10.1503/cjs.012013

3. Cassidy JT, Baker JF, Lenehan B. The Role of Prognostic Scoring Systems in Assessing Surgical Candidacy for Patients With Vertebral Metastasis: A Narrative Review. Global Spine J. 2018;8(6):638–651. doi:10.1177/2192568217750125

4. Péus D, Newcomb N, Hofer S. Appraisal of the Karnofsky Performance Status and proposal of a simple algorithmic system for its evaluation. BMC Med Inform Decis Mak. 2013;13:72. Published 2013 Jul 19. doi:10.1186/1472-6947-13-72

5. Schoenfeld AJ, Blucher JA, Barton LB, et al. Design of the prospective observational study of spinal metastasis treatment (POST) [published online ahead of print, 2019 Nov 8]. Spine J. 2019;S1529-9430(19)31068-X. doi:10.1016/j.spinee.2019.10.021

Back to Profiles