Predictive Scores Underestimate Survival of Patients With Metastatic Spine Disease

A Retrospective Study of 315 Patients in Sweden

Christian Carrwik, MD; Claes Olerud, MD, PhD; Yohan Robinson, MD, PhD, MBA

Disclosures

Spine. 2020;45(6):414-419. 

In This Article

Abstract and Introduction

Abstract

Study Design: Retrospective cohort study.

Objective: To validate the precision of four predictive scoring systems for spinal metastatic disease and evaluate whether they underestimate or overestimate survival.

Summary of Background Data: Metastatic spine disease is a common complication to malignancies. Several scoring systems are available to predict survival and to help the clinician to select surgical or nonsurgical treatment.

Methods: Three hundred fifteen adult patients (213 men, 102 women, mean age 67 yr) undergoing spinal surgery at Uppsala University Hospital, Sweden, due to metastatic spine disease 2006 to 2012 were included. Data were collected prospectively for the Swedish Spine Register and retrospectively from the medical records. Tokuhashi scores, Revised Tokuhashi Scores, Tomita scores, and Modified Bauer Scores were calculated and compared with actual survival data from the Swedish Population Register.

Results: The mean estimated survival time after surgery for all patients included was 12.4 months (confidence interval 10.6–14.2) and median 5.9 months (confidence interval 4.5–7.3). All four scores had significant correlation to survival (P < 0.0001) but tended to underestimate rather than overestimate survival. Modified Bauer Score was the best of the four scores to predict short survival, both regarding median and mean survival. Tokuhashi score was found to be the best of the scores to predict long survival, even though the predictions were inaccurate in 42% of the cases.

Conclusion: Predictive scores underestimate survival for the patients which might affect important clinical decisions.

Level of Evidence: 3

Introduction

Patients with metastatic spine disease often present with acute symptoms such as neurological impairment or unbearable pain. The spine surgeon's decision on whether the patient will benefit from surgery or not is based on several factors, where the expected survival time probably is the most important.

To facilitate the decision making, several scoring systems are available and widely used. The Tokuhashi Score was published by Tokuhashi et al 1990[1] and revised in 2005.[2] Tomita et al published their scoring system in 2001,[3] whereas the Bauer score was introduced already in 1995.[4]

There are several studies where these and other scoring systems are validated retrospectively.[5–8] In recent years, several papers suggest that the scoring systems tend to underestimate survival and are lagging behind advancements in oncology.

From the clinician's perspective, the scores should assist in selecting patients who will have an estimated survival long enough to justify the potential risks with the surgery. On the contrary, patients with short expected survival should not be exposed to high-risk surgery with little chance of increasing their quality of life during the remainder of their lives.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....