Navigating the Landscape of Liver Cancer Management: Study Designs in Clinical Trials and Clinical Practices

: Randomized controlled trials (RCTs) represent the gold standard for evidence generation across all areas of medicine and especially in the oncology field, as they allow unbiased estimates of treatment effect without confounders. Observational studies have many problems that could reduce their internal and external validity. However, large prospective (well-conducted) observational real-world studies (RWS) can detect the occurrence of rare adverse events or monitoring for long-term adverse events. Impact of Real Word Data (RWD), which refers to data generated from routine, standard care of patients, and real-world 'evidence' (RWE), which is the evidence generated from RWD represent an open challenge. Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer death worldwide and its prognosis is highly heterogeneous, being related not only to tumor burden but also to the severity of underlying chronic liver disease. Moreover, advances in systemic therapies for HCC have increased the complexity of HCC patient management. Aim of this review article is to provide an overview of the benefits and limitations of different study designs, particularly focusing on RCTs and observational studies, to address important and not fully resolved questions in HCC research.