The prognostic role of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune-inflammation index on short- and long-term outcome following surgery for spinal metastases

OBJECTIVE Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) have shown promise in predicting mortality in various types of cancer. The purpose of this study was to assess NLR, PLR, and SII in predicting 30-day mortality and overall survival (OS) among surgically treated patients with spinal metastasis. METHODS This was a retrospective study including 153 patients who underwent surgery for spinal metastasis between 2012 and 2022. Electronic medical records were manually reviewed, and NLR, PLR, and SII were calculated from preoperative neutrophil, platelet, and lymphocyte counts. Receiver operating characteristic curves with areas under the curve were generated to determine cutoff values. Logistic regression was used to determine the odds ratios (ORs) for 30-day mortality. The Kaplan-Meier method and Cox regression were used to determine the hazard ratio (HR) for OS limited to 5 years postoperatively. RESULTS Preoperative cutoff values were as follows: NLR > 10.2, PLR > 260, and SII > 2900. Overall, 35.9% (55/153) of patients had elevated NLR, 45.7% (70/153) had elevated PLR, and 30.7% (47/153) had elevated SII. The overall 30- day mortality was 8.5% (13/153). After controlling for confounders such as performance status and primary tumor type, high NLR (OR 5.20, 95% CI 1.21-22.28; p = 0.026) and SII (OR 4.92, 95% CI 1.17-20.63; p = 0.029) were associated with increased odds of 30-day postoperative mortality. The median OS time in the study population was 26 months (95% CI 12-40 months). After controlling for confounders such as Eastern Cooperative Oncology Group status, primary tumor, and hypoalbuminemia, high NLR was associated with shorter OS (HR 2.23, 95% CI 1.48-3.97; p = 0.003). CONCLUSIONS High preoperative NLR and SII were independently associated with 30-day postoperative mortality in this study. Elevated NLR was also found to be associated with shorter OS. The prognostic role of these metrics warrants further investigation.