High prognostic nutritional index could be associated with improved survival in patients with brain metastases: a retrospective observational study

Abstract

ABSTRACT Background Prognostic nutritional index (PNI) is an indicator of immunonutritional status. The present study aimed to evaluate the association between PNI and overall survival in patients with brain metastases. Methods A total of 257 patients with histologically confirmed brain metastasis who underwent surgery at our center between April 2011 and April 2021 were investigated retrospectively. Demographic, clinical, and radiologic data of all cases were extracted. Patients were divided into the low PNI group(PNI <45) (malnutrition status) and the high PNI group (PNI ≥45)(normal nutritional status). Survival analyses were performed using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using the Cox proportional hazards method. Results From the 257 cases of brain metastases, there were 148 (57.6%) males and 109 (42.4%) females. The mean age was 57.02 ± 8.7. The median overall survival was 13 months. The results of the multivariate Cox regression analyses showed primary cancer site (HR 2.196, 95% CI 1.988–6.52605, P = 0.000), the number of metastases (HR 1.829, 95% CI 1.380–2.872, P = 0.037), extracranial involvement (HR 2.186, 95% CI 1.213–4.171, P = 0.026), adjuvant radiotherapy (HR 2.823, 95% CI 1.187–5.415, P = 0.017) and PNI (HR 1.961, 95% CI 1.168–3.515, P = 0.021) as the independent predictors of overall survival in patients with brain metastases. Conclusion Our results suggest that PNI could be associated with survival in patients with brain metastases. Patients with a lower PNI had a significantly worse outcome in comparison with those with a higher PNI. Evaluation of PNI may provide additional prognostic information in patients with brain metastases.