Preoperative platelet count as an independent predictor of long-term outcomes among patients undergoing resection for intrahepatic cholangiocarcinoma

Background and Objectives: An elevated platelet count may reflect neoplastic and inflammatory states, with cytokine-driven overproduction of platelets. The objective of this study was to evaluate the prognostic utility of high platelet count among patients undergoing curative-intent liver surgery for intrahepatic cholangiocarcinoma (ICC). Methods: An international, multi-institutional cohort was used to identify patients undergoing curative-intent liver resection for ICC (2000–2020). A high platelet count was defined as platelets >300 *109/L. The relationship between preoperative platelet count, cancer-specific survival (CSS), and overall survival (OS) was examined. Results: Among 825 patients undergoing curative-intent resection for ICC, 139 had a high platelet count, which correlated with multifocal disease, lymph nodes metastasis, poor to undifferentiated grade, and microvascular invasion. Patients with high platelet counts had worse 5-year (35.8% vs. 46.7%, p = 0.009) CSS and OS (24.8% vs. 39.8%, p < 0.001), relative to patients with a low platelet count. After controlling for relevant clinicopathologic factors, high platelet count remained an adverse independent predictor of CSS (HR = 1.46, 95% CI 1.02–2.09) and OS (HR = 1.59, 95% CI 1.14–2.22). Conclusions: High platelet count was associated with worse tumor characteristics and poor long-term CSS and OS. Platelet count represents a readily-available laboratory value that may preoperatively improve risk-stratification of patients undergoing curative-intent liver resection for ICC.