Conversion therapy for initially unresectable hepatocellular carcinoma: Current status and prospects

Research has shown that locoregional and/or systemic treatments can reduce the tumor stage, enabling radical surgical resection in patients with initially unresectable hepatocellular carcinoma. This is referred to as conversion therapy. Patients who undergo conversion therapy followed by curative surgery experience a significant survival benefit compared to those who receive chemotherapy alone, those who are successfully downstaged with conversion therapy but not treated with surgery, or those who are treated with upfront surgery. Several treatments have been studied as conversion therapy. However, the success rate of conversion varies greatly, ranging from 0.8% to 60%. Combined locoregional plus systemic conversion therapy has demonstrated significant clinical advantages, with a conversion rate of up to 60%, an objective remission rate of 96% for patients, and a disease control rate of up to 100%. However, patients who underwent conversion therapy experienced significantly more complications than those who underwent direct LR without conversion therapy. Conversion therapy can cause hepatotoxicity, bone marrow suppression, local adhesions, increased fragility of blood vessels and liver tissues, and hepatic edema, which can increase the difficulty of surgery. In addition, criteria need to be established to evaluate the efficacy of conversion therapy and subsequent treatment. Further clinical evidence in this area is urgently needed.