High platelet-to-lymphocyte ratio is associated with poor prognosis in patients with unresectable intrahepatic cholangiocarcinoma receiving gemcitabine plus cisplatin

BACKGROUND: Several systemic inflammatory response (SIR) markers, including platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and albumin-to-globulin ratio (AGR), have emerged as prognostic markers in various cancers. The aim of this study was to explore the impact of SIR markers on the survival outcomes of unresectable intrahepatic cholangiocarcinoma (IHC) patients. METHODS: Patients with histologically confirmed, unresectable IHC treated with gemcitabine plus cisplatin (GP) chemotherapy in a single tertiary hospital from 2012 to 2016 were retrospectively reviewed. Progression-free survival (PFS) and overall survival (OS) were determined using unadjusted Kaplan-Meier and adjusted Cox-proportional-hazards analysis. Time-dependent receiver operating characteristic (ROC) analysis was performed to compare the performance of the SIR markers in predicting OS. RESULTS: A total of 137 patients received a median of six cycles (interquartile range [IQR], 3–11) of GP chemotherapy with a median observation time of 9.9 months (range, 1.8–54.7 months). The median PFS and OS of all patients were 7.8 months and 9.9 months, respectively. Among the SIR markers, high PLR (> 148) and high NLR (> 5) were associated with a short PFS (Hazard ratio [HR] 1.828, P = 0.006; HR 1.738, P = 0.030, respectively) and short OS (HR 2.332, P < 0.001; HR 2.273, P < 0.001, respectively). Low LMR (< 3.5) and low AGR (< 1.2) were associated with a short OS (HR 2.423, P < 0.001; HR 1.768, P = 0.002, respectively). In multivariable cox-regression analysis, high PLR (HR 1.766, P = 0.009) and distant lymph node (LN) metastasis (HR 2.085, P = 0.001) were associated with a short PFS. High PLR (HR 1.856, P = 0.002) was an independent predictor of a short OS, along with distant LN metastasis (HR 1.929; P < 0.001), low LMR (HR 1.691; P = 0.041), and low level of serum albumin (< 3.5 g/dL) (HR 1.632; P = 0.043). Time-dependent ROC analysis revealed that the area under the curve of PLR for predicting overall survival was greater than that of NLR, LMR, and AGR at most time points. CONCLUSIONS: High PLR was an independent prognostic factor of a short PFS and OS in patients with unresectable IHC receiving GP chemotherapy.