Utility of AST to platelet ratio index (APRI) score in predicting post-surgical outcomes in patients with cholangiocarcinoma.

Abstract

502 Background: Cholangiocarcinoma (CCA) is an epithelial malignancy of the intrahepatic or extrahepatic biliary tree, primarily driven by chronic inflammation and fibrosis. Given fibrosis has shown to correlate with malignancy and the aminotransferase-platelet ratio index (APRI) score, a marker for hepatic fibrosis, has shown to be useful in prognosticating hepatocellular carcinoma, this study aimed to assess the utility of APRI score in prognosticating post-surgical outcomes in CCA patients. Methods: 152 CCA patients at the Mayo Clinic that underwent surgical resection were retrospectively analyzed. Statistical analyses were then conducted to determine the relationship between APRI score and demographic factors, laboratory values (CA19-9, albumin, bilirubin, INR, alkaline Phosphatase, ALT, AST, and platelet count), pathology features, and outcome data. Results: When looking at demographic factors, no relationship between APRI score and age (r = -0.19, p = 0.02), sex (2-sample t-test p = 0.16) and race (ANOVA p = 0.81) were identified. There was a negative correlation between APRI score and albumin (m = -0.35, r = -0.35, p < 0.01) and a positive correlation with bilirubin (m = 0.13, r = 0.23, p = 0.01) and ALT (m = 0.01, r = 0.47, p < 0.01). No correlation between the other laboratory values analyzed was identified. Similarly, there was no relationship between APRI score and pathology features (tumor grade t-test p = 0.41, N Stage ANOVA p = 0.94, Vascular Invasion t-test p = 0.59, and Perineural invasion t-test p = 0.14), except for T3 stage which had a higher APRI score compared to T1, T2, and T4 (ANOVA p = 0.01). Likewise, APRI also did not correlate with post-surgical outcomes like recurrence (t-test p = 0.22) and mortality (t-test p = 0.39). Conclusions: In summary, despite being driven by chronic inflammation, APRI score, a marker for hepatic inflammation and a surrogate for liver fibrosis, did not serve as a reliable prognostication tool of post-surgical outcomes in CCA patients. These data suggest that although chronic inflammation is thought to be one of the primary drivers of disease, the role of other factors such as genetic and cellular signaling abnormalities may play a more prominent role in patients with CCA. In conclusion, APRI score did not serve as a useful prognostication tool in surgically resected CCA patients. Future studies should focus on other prognostic factors such as genomic and transcriptomic biomarkers in CCA.