Lymphopenia predicts 30-day morbidity and mortality following spinal metastasis surgery

BACKGROUND: Therapeutic decision-making regarding surgical treatment of spinal metastasis is supported by clinical characteristics that are potentially predictive of postoperative events. The predictive power of total lymphocyte count (TLC) in peripheral blood has not been elucidated for this type of surgery. Therefore, the aim of this study was to assess the capacity of TLC to predict 30-day morbidity and mortality following surgery for spinal metastases. METHODS: This is a level III prognostic study, which consists of a retrospective review of records from a cancer referral hospital. Consecutive patients who underwent open surgery for spinal metastatic disease were studied. Outcomes of interest were 30-day post-op mortality and complications. The patients were divided into three groups based on preoperative TLC: low, moderate, and high risk for surgery, according to a discriminatory power analysis. The predictive power of TLC was compared to that of other known predictors, i.e., older age, tumor aggressiveness, and presence of comorbidities. Odds ratios (ORs) and 95% confidence intervals were calculated using bivariate and multivariate analyses. RESULTS: In total, 205 patients underwent surgery. Thirty-day mortality and occurrence of complications were 17% and 31%, respectively. The discriminatory power of TLC was 71% and 68% for 30-day survival and complications, respectively. In multivariate analysis, the strongest relationship between predictors and postoperative morbidity and mortality concerned TLC < 800 cells/µL, which was associated with decreased likelihood of 30-day survival (OR 3.17) and increased likelihood of complications (OR 3.93). Incidence of 30-day mortality and complications by risk group was, respectively: 4% and 13% for low risk (TLC > 1857 cells/µL); 22% and 34% for moderate risk (TLC 800-1857 cells/µL); and 35% and 56% for high risk (TLC < 800 cells/µL). CONCLUSIONS: TLC is a strong predictor of 30-day morbidity and mortality following spinal metastasis surgery. It may be useful for improving patient care and planning personalized treatments.