Prospective evaluation of the clinical implications of the tumor metabolism and chemotherapy-related changes in advanced biliary tract cancer.

Abstract

261 Background: Tumor metabolism measured by [18F] fluorodeoxy-D-glucose (18F-FDG) positron emission tomography (PET) has a diagnostic and prognostic role in several cancers. The clinical implication of tumor metabolism in biliary tract cancer (BTC) has not been studied well. Therefore, we prospectively evaluated the prognostic value of tumor metabolism and chemotherapy-related changes in advanced BTC patients. Methods: We prospectively enrolled advanced BTC patients before the initiation of palliative chemotherapy. Using 18F-FDG PET, we assessed the baseline maximum standardized uptake value (SUVmax) and monitored the changes of SUVmax during chemotherapy. We analyzed the associations between SUVmax, and clinicopathologic factors and clinical outcomes. Results: A total of 75 patients were enrolled. All patients received gemcitabine/cisplatin as first-line chemotherapy. Primary tumor site, histologic differentiation, molecular characteristics, laboratory findings, and disease extent were associated with the metabolic characteristics. The high metabolism group showed worse survival outcome [Hazard ratio (HR)=4.09, p=0.001 for progression-free survival (PFS); HR=2.61, p=0.019 for overall survival (OS)] than the low metabolism group. The lesser reduction of SUVmax during chemotherapy was also associated with worse outcome (HR=3.35, p=0.002 for PFS; HR=1.96, p=0.082 for OS). Considering both baseline tumor metabolic activity and chemotherapy-related changes in the tumor metabolism, patients with a low metabolism and a more reduction in metabolism obtained the best OS (20.7 months, p=0.013). Conclusions: Tumor metabolic activity and the chemotherapy-related changes in the metabolism were associated with prognosis in advanced BTC patients.