In patients with initially unresectable colorectal liver metastasis, neoadjuvant chemotherapy can result in tumor shrinkage and some tumors can be considered to be unresectable to resectable. Aggressive surgery in those patients is called conversion surgery. Recent progress of chemotherapy, molecular target therapy, and surgical procedures, such as portal vein embolization, staged hepatectomy, and associating liver partition and portal vein ligation for staged hepatectomy increase the proportion of conversion surgery in those patients.
In this lecture, I will deal with following topics.
First, recent consensus key definition of resectability of colorectal liver metastasis is ability to remove all metastatic deposits leaving an adequate liver remnant. This definition looks simple and clear. However, it is challenging how RO resection be achieved in patients with bilobar multiple liver metastases. In clinical practice, resectability is still influenced by several variables, such as surgeon experience and innovative radiological and surgical techniques.
Second, selection of chemotherapeutic and molecular target agents can affect tumor response rate and conversion rate in those patients. I’ll try to figure out what kind of therapy should be selected to convert the initially inresectable colorectal liver metastasis.
Finally, chemotherapy and molecular target agents can accompany side effects, which are chemotherapy induced liver damage and vanishing lesions. Chemotherapy induced steatosis, steatohepatitis and sinusoidal injury will be reviewed and then optimal chemotherapy cycles and timing of liver resection will be discussed. Optimal management of vanishing lesions will be also reviewed.