Treatment of hepatocellular carcinoma in the Precision Medicine era: from treatment stage migration to therapeutic hierarchy

Treatment allocation is extremely complex in patients with hepatocellular carcinoma (HCC) because this neoplasm arises, in most cases, in patients with cirrhosis and additional comorbidities. "Stage hierarchy" approach, which involves linking each stage (or sub-stage) of the disease to a specific treatment, has become the main proposed treatment strategy for the clinical management of HCC, particularly in the West. The Barcelona Clinic Liver Cancer (BCLC) scheme serves as the main example of the application of this strategy. In an attempt to increase the plasticity of the "stage hierarchy" approach as well as its adaptability to the requirements of real-world clinical practice, the latest version of European and American guidelines have introduced certain relevant elements of flexibility, which were not intrinsic to the original BCLC scheme. These elements are as follows: the "treatment stage migration" strategy, which allows moving to another treatment (generally the one that is associated with the subsequent stage) if the approach linked with the current stage proves to be unfeasible; and the "treatment stage alternative" approach, which proposes further therapeutic options for each BCLC-defined stage. In regard to most of the solid cancers, another potential strategy is to consider the treatment decision to be hierarchically dictated by the efficacy of each therapy with complete or partial independence from the tumor stage. This concept of "therapeutic hierarchy" has been historically endorsed by the Asia-Pacific treatment algorithm as well as by the recent Italian multi-society guidelines. The present review provides a critical analysis of the different conceptual approaches to HCC management, highlighting their advantages and disadvantages, and focusing on the remarkable differences between the stage-guided and the hierarchical strategies.