Prognostic Nutritional Index (PNI) and Neutrophil to Lymphocyte Ratio (NLR) as Predictors of Short-Term Survival in Patients with Advanced Malignant Biliary Obstruction Treated with Percutaneous Transhepatic Biliary Drainage

Abstract

Background: Effective biliary tree decompression plays a central role in the palliation of malignant biliary obstruction (MBO). When endoscopic drainage is unfeasible or unsuccessful, percutaneous transhepatic biliary drainage (PTBD) is the method of choice and preferred treatment approach in advanced hilar MBO. The prognostic nutritional index (PNI) reflects the patient’s immunonutritional status, while the neutrophil to lymphocyte ratio (NLR) reflects the patient’s inflammation status. The aim of the present study was to evaluate the prognostic value of preprocedural PNI and NLR on short-term survival in the advanced stage MBO population threatened with PTBD and to characterize the differences in immunonutritional and inflammatory status between 60-day survivors and non-survivors, as well as analyze other variables influencing short-term survival. Methods: This single-center retrospective study was conducted on patients undergoing palliative PTBD caused by MBO as a definitive therapeutic treatment between March 2020 and February 2022. After the procedure, patients were followed until the end of August 2022. Results: A total of 136 patients with malignant biliary obstruction were included in the study. Based on receiver operating characteristic (ROC) curve analysis, optimal cut off-values for NLR (3) and PNI (36.7) were determined. In univariate regression analysis, age, absolute neutrophil count, albumin level, NLR ≤ 3, and PNI ≥ 36.7 were significant predictors of 60-day survival. Level of obstruction and PNI ≥ 36.7 were statistically significant independent predictors of 60-day survival in a multivariate regression model. Using PNI ≥ 36.7 as a significant coefficient from the multivariate regression model with the addition of NLR ≤ 3 from univariate analysis, a 60-day survival score was developed. Conclusions: PNI and NLR are easy to calculate from routine blood analysis, which is regularly conducted for cancer patients. As such, they represent easily available, highly reproducible, and inexpensive tests capable of expressing the severity of systemic inflammatory responses in patients with cancer. Our study highlights that preprocedural PNI and NLR values provide predictors of short-term survival in patients with MBO treated with palliative PTBD. In addition, the proposed 60-day survival score can contribute to better selection of future candidates for PTBD and recognition of high-risk patients with expected poor outcomes.