The past, present and future of conversion therapy for liver cancer

Primary liver cancer is one of the world's most common malignant tumors, as well as the malignant tumor with the third highest mortality rate in China. Most Chinese patients with liver cancer already have intermediate or advanced stage disease at initial diagnosis and have lost the opportunity for surgery. Following recent advances in treatments for advanced liver cancer, the associated treatment efficacy and response rates have continuously improved. As a result, the application of preoperative treatments can lead to tumor downstaging in a high proportion of patients and consequently provide initially ineligible patients with opportunities for surgical intervention, representing a breakthrough treatment strategy for liver cancer. Since conversion study is still in its infancy, there remain controversies in terms of patient selection, choice of treatment method, and postoperative management. In this review, we collect and summarize current evidence and clinical experience of conversion therapy, highlight remaining problems and challenges and provide a foundation for further research and development of HCC treatment in clinical practice.