Laboratory markers as useful prognostic measures for survival in patients with spinal metastases

Abstract

BACKGROUND CONTEXT Laboratory values have been found to be useful predictive measures of survival following surgery. The utility of laboratory values for prognosticating outcomes among patients with spinal metastases has not been studied. PURPOSE To determine the prognostic capacity of laboratory values at presentation including white blood cell (WBC) count, serum albumin and platelet-lymphocyte ratio (PLR) in patients with spinal metastases. STUDY DESIGN Retrospective review of records from two tertiary care centers (2005-2017). PATIENT SAMPLE Patients, aged 40-80, who received operative or nonoperative management for spinal metastases. OUTCOME MEASURES Survival, complications or hospital readmissions within 90 days of treatment and a composite measure for treatment failure accounting for changes in ambulatory function and mortality at 6 months following presentation. METHODS Multivariable Cox proportional hazard regression analysis was used to analyze the relationship between laboratory values and length of survival, adjusting for confounders. Multivariable logistic regression was used in analyses related to 6-month and 1-year mortality, complications, readmissions and treatment failure. A scoring rubric was developed based on the performance of laboratory values in the multivariable tests. Internal validation was performed using a bootstrap simulation that consisted of sampling with replacement and 1,000 replications. RESULTS We included 1,216 patients. Thirty-seven percent of patients received a surgical intervention and 63% were treated nonoperatively. Median survival for the cohort as a whole was 255 days (inter-quartile range 93-642 days). PLR (HR 1.53; 95% CI 1.29, 1.80; p<0.001) and albumin (HR 0.54; 95% CI 0.45, 0.64; p<0.001) were significantly associated with survival, while WBC count (HR 1.08; 95% CI 0.86, 1.36; p=0.50) was not associated with this outcome. Similar findings were encountered for 6-month and 1-year mortality as well as the composite measure for treatment failure. PLR and albumin performed well in our scoring rubric and findings were preserved in the bootstrapping validation. CONCLUSIONS Individuals with low serum albumin and elevated PLR should be advised regarding the impact of these laboratory markers on outcomes including survival, irrespective of treatments received. An effort should also be made to optimize nutrition and PLR, if practicable, prior to treatment to minimize the potential for development of adverse events. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Laboratory values have been found to be useful predictive measures of survival following surgery. The utility of laboratory values for prognosticating outcomes among patients with spinal metastases has not been studied. To determine the prognostic capacity of laboratory values at presentation including white blood cell (WBC) count, serum albumin and platelet-lymphocyte ratio (PLR) in patients with spinal metastases. Retrospective review of records from two tertiary care centers (2005-2017). Patients, aged 40-80, who received operative or nonoperative management for spinal metastases. Survival, complications or hospital readmissions within 90 days of treatment and a composite measure for treatment failure accounting for changes in ambulatory function and mortality at 6 months following presentation. Multivariable Cox proportional hazard regression analysis was used to analyze the relationship between laboratory values and length of survival, adjusting for confounders. Multivariable logistic regression was used in analyses related to 6-month and 1-year mortality, complications, readmissions and treatment failure. A scoring rubric was developed based on the performance of laboratory values in the multivariable tests. Internal validation was performed using a bootstrap simulation that consisted of sampling with replacement and 1,000 replications. We included 1,216 patients. Thirty-seven percent of patients received a surgical intervention and 63% were treated nonoperatively. Median survival for the cohort as a whole was 255 days (inter-quartile range 93-642 days). PLR (HR 1.53; 95% CI 1.29, 1.80; p<0.001) and albumin (HR 0.54; 95% CI 0.45, 0.64; p<0.001) were significantly associated with survival, while WBC count (HR 1.08; 95% CI 0.86, 1.36; p=0.50) was not associated with this outcome. Similar findings were encountered for 6-month and 1-year mortality as well as the composite measure for treatment failure. PLR and albumin performed well in our scoring rubric and findings were preserved in the bootstrapping validation. Individuals with low serum albumin and elevated PLR should be advised regarding the impact of these laboratory markers on outcomes including survival, irrespective of treatments received. An effort should also be made to optimize nutrition and PLR, if practicable, prior to treatment to minimize the potential for development of adverse events.