Neurosurgery Resident Montefiore Einstein Neurosurgery Bronx, New York, United States
Introduction: Prognostication of postoperative survival is important in the decision-making process for patients with spinal metastases. Nutritional status has been associated with poor outcome and limited survival in the general cancer population. The objective of this study is to evaluate the utility of the prognostic nutritional index (PNI) for prediction of postoperative mortality after metastatic spinal tumor surgery.
Methods: A total of 139 patients who underwent oncological surgery for metastatic spine disease between April 2012 and August 2022 and had a minimum follow-up of 90 days were included in this study. The mean age of the population was 63 years and 59% were male (82 of 139). The PNI was calculated using the preoperative serum albumin level and total lymphocyte counts; the mean PNI for the group was 43 (standard deviation: 7.7). Low PNI was defined as patients with PNI < 40. The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed.
Results: The 90-day mortality rate was 27% (37 of 139). After controlling for factors such as age, ECOG performance status, total psoas muscle cross-sectional area (TPA), and primary cancer site, the PNI was independently associated with 90-day mortality (odds ratio 0.86 [95% confidence interval 0.79 to 0.94]; p = 0.001). The 12-month mortality rate was 56% (51 of 91). After controlling for variables such as ECOG performance status, and primary cancer site, the PNI was independently associated with 12-month mortality (OR 0.89 [95% CI 0.82 to 0.97]; p = 0.008). Patients with low PNI ( < 40) had a 50% mortality rate at 90 days and 84% mortality rate at 12 months.
Conclusion : The PNI was found to be independently associated with 90-day and 12-month mortality after metastatic spinal tumor surgery in this study, independent of performance status, TPA, and primary cancer site. Prospective validation of this metric as a prognostic factor is needed.
How to Improve Patient Care: The PNI needs to be further validated but can be used as part of the armamentarium to prognosticate postoperative survival in patients with spinal metastases.
