Extending Surgical Resection for Hepatocellular Carcinoma Beyond Barcelona Clinic for Liver Cancer (BCLC) Stage A: A Novel Application of the Modified BCLC Staging System.

503 Background: Intermediate hepatocellular carcinoma is a heterogenous group of disease. We aimed to prognosticate survival after surgical resection of HCC stratified by stage with amalgamation of the modified Barcelona Clinic Liver Cancer (BCLC) staging system and location of tumour. Methods: This single-institutional retrospective cohort study included patients with HCC who underwent surgical resection between 1 st January 2000 to 30 th June 2016. Participants were divided into 6 different subgroups based on the Milan Criteria (MC), the “Up-to-7” criteria, and location of lesions: A-u) Within MC with Unilobar lesions; A-b) Within MC + Bilobar lesions; B1-u) Out of MC + within Up-To-7 + Unilobar lesions; B1-b) Out of MC + within Up-to-7 + Bilobar lesions; B2-u) Out of MC + Out of Up-To-7 + Unilobar lesions; B2-b) Out of MC + Out of Up-To-7 + Bilobar lesions. A separate survival analysis was conducted for solitary HCC lesions according to three subgroups: A-S (Within MC); B1-S (Out of MC + within Up-To-7); B2-S (Out of MC + out of Up-To-7). The respective primary and secondary time-to-event outcomes were overall survival (OS) and recurrence-free survival (RFS). Results: 794 of 1043 patients with surgical resection for HCC were analysed. Groups A-u (64.6 %), A-b (58.4 %) and B1-u (56.2 %) had 5-year cumulative overall survival (OS) rates above 50% after surgical resection and median OS exceeding 60 months (P=0.0001). The 5-year cumulative recurrence-free survival rates (RFS) were 40.4% (group A-u), 38.2% (group A-b), 36.3% (group B1-u), 24.6% (group B2-u), and 7.3% (group B2-b)(P=0.0001). For solitary lesions, the 5-year OS for the subgroups were A-S (65.1%), B1-S (56.0%) and B2-S (47.1%) (P=0.0003). Compared to A-S, there was also a significant trend towards relatively poorer OS as the lesion sizes increased in B1-S (HR 1.46, 95%CI 1.03 – 2.08) and B2-S (HR 1.65, 95%CI 1.25 – 2.18). Conclusions: We adopted a novel approach combining the modified BCLC B sub-classification and dispersion of tumour to show that surgical resection may be curative in a select subgroup of patients with intermediate HCC that fall outside BCLC Stage A, specifically those with unilobar lesions and are within the “up-to-7” criteria. Furthermore, We found that size prognosticates resection outcomes in solitary tumours.