Rethinking of the conversion therapy in colorectal cancer patients with liver metastasis

The incidence of colorectal cancer liver metastasis (CRLM) has gradually increased in recent years. Surgical resection is the main method to achieve long-term survival for patients with CRLM. However, only 20% of these patients have the chance to undergo surgical resection. If the unresectable metastases can be converted to resectable ones by effective conversion therapy, the 5-year survival rate of patients received liver resection can exceed to 30%, which is significantly better than palliative treatment. Therefore, for patients who are initially unresectable, rationally developing a conversion therapy strategy to convert the initial unresectable CRLM into resectable ones is the key to improve the long-term survival of CRLM patients. However, there are still many controversies in clinical practice. In this article, we discuss three critical issues related to the conversion therapy for CRLM based on previous related researches and our experience, including the applicable population of conversion therapy, how to choose a conversion regime and the recognition and treatment of disappeared lesions after chemotherapy. Key words: Colorectal neoplasms; Metastasis, liver; Drug therapy; Conversion therapy