Recent advances in systemic therapy for hepatocellular carcinoma (HCC) have led to debates about the feasibility of combination therapies, such as systemic therapy combined with surgery or transarterial chemoembolization, for patients with advanced HCC. However, a lack of consensus on the oncological resectability criteria has hindered discussions of “conversion therapy” and the optimal management in patients with HCC. To address this issue, the Japan Liver Cancer Association (JLCA) and the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS) established a working group and discussed the concept of borderline resectable HCC. Herein, we present a consensus statement from this expert panel on the resectability criteria for HCC from the oncological standpoint under the assumption of technically and liver-functionally resectable situations. The criteria for oncological resectability in HCC are classified into three grades: resectable, representing an oncological status for which surgery alone may be expected to offer clearly better survival outcomes as compared with other treatments; borderline resectable 1, representing an oncological status for which surgical intervention as a part of multidisciplinary treatment may be expected to offer survival benefit; and borderline resectable 2, representing an oncological status for which the efficacy of surgery is uncertain and the indication for surgery should be determined carefully under the standard multidisciplinary treatment. These criteria aim to provide a common language for discussing and analyzing the treatment strategies for advanced HCC. It is also expected that these criteria will be optimized, modified, and updated based on further advancements in systemic therapies and future validation studies.

Introduction: For prognostication of hepatocellular carcinoma (HCC), the optimal size cutoff value and the significance of microvascular invasion (mvi) remain inconclusive. Objective: This study sought to revisit the inconclusive components of current American Joint Committee on Cancer (AJCC) staging system and to develop a new practical prognostication model for patients with HCC based on 2 large cohorts. Method: In 1,175 patients who underwent resection for HCC (training cohort), prognostic significance of mvi, and optimal size cutoff value were revisited and a new staging model was established. Then, its performance was validated using 5,249 patients derived from a population-based database (validation cohort). Results: The optimal size cutoff value was 2 cm in multiple HCC, similar to that for solitary HCC. Multivariate analyses confirmed that mvi, a size >2 cm, and multiple lesions were independent predictors with similar weights for disease-specific survival. Based on these results, earlier stages of HCC were reclassified according to the number of the following factors: multiple tumors, >2 cm in diameter, and presence of mvi. Also, given the similar prognosis of Stages IIIB and IVA according to the AJCC 8th edition, these groups were reclassified into the same stage. This new staging model had a better performance than the AJCC 8th edition in both training cohort (c-statistics, 0.648 vs. 0.629) and the validation cohort (c-statistics, 0.646 vs. 0.645) regardless of the presence of cirrhosis. Conclusions: Inclusion of a size cutoff value of 2 cm and mvi could reclassify the current version of the AJCC staging system and offer an alternative prognostication model using a single size-cutoff value of HCC.