Risk stratification for locally advanced hepatocellular carcinoma using pretreatment alpha-foetoprotein and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography

Background & Aims: We investigated the significance of ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (¹⁸F-FDG PET) parameters and alpha-foetoprotein (AFP) levels in patients with locally advanced hepatocellular carcinoma (LA-HCC). Methods: We retrospectively analysed data of 228 patients with LA-HCC who underwent pretreatment ¹⁸F-FDG PET between January 2003 and December 2013. All patients were treated using liver-directed therapy involving radiotherapy. The maximum standardized uptake values (SUVs) and tumour-to-extratumoural liver SUV ratios were calculated, and pretreatment AFP values were obtained. Results: Patients were divided into high and low maximum SUV (SUVmax) groups according to a SUV cut-off of 4.825 determined via receiver-operating characteristic analysis. High AFP level (>550 ng/mL) and high SUVmax were significant predictors of overall and progression-free survival. Better treatment responses and longer median progression-free and overall survival were observed in the low SUVmax group, compared to the high SUVmax group. Similar results were obtained for SUV ratio-based (cut-off value: 2.355) and AFP-based analyses (cut-off value: 550 ng/mL). Three risk groups were identified using the double biomarkers of SUVmax and AFP value as strong prognosticators predictive of survival outcomes. This risk stratification was identified as a prognosticator of survival outcomes, even after subgroup analyses. Furthermore, in high risk group, significantly high extrahepatic failure was shown while in low risk group, significantly low intrahepatic failure. Conclusions: Clinical significance of double biomarkers, SUV and AFP, could be translated into risk stratification for LA-HCC. It could be a valuable tool for survival outcome prediction.