Preoperative Chemotherapy Can Change the Surgical Procedure for Hepatectomy in Patients with Liver Metastasis of Colorectal Cancer

Aim: The benefit of preoperative chemotherapy is evaluated in order to clarify the relationship of tumor site with hepatic vessels for hepatectomy. Tumor location in relation to intrahepatic vessels is critical in the decision to operate, but the argument for this concept remains insufficient. Currently, the response rate is evaluated by the decrease in size or number of tumors but not by hepatic resection range.

Patients and methods: We evaluated 32 patients who underwent hepatectomy after chemotherapy for liver metastases from colorectal cancer (CLM). Tumor diameter was defined by contrast computed tomographic imaging before both chemotherapy and surgery. The targeted vessels were those in the main Glisson capsule and hepatic vein and were indicated to change in the resected area by their treatment.

Results: Tumor size decreased, increased or remained unchanged in 62 (68.9%), 27 (30.0%) and one (1.1%) tumor, respectively. Out of the 29 tumors, reduced resection volume was achieved in 12 (37.9%), and the difference in volume was 17.4±4.15 ml. A significant positive correlation was found between tumor shrinkage rate and final distance from the attached vessels (p=0.017), and a shrinkage rate of 63.6±12.4% was necessary for a tumor to be separated from an attached vessel. The final distance was significantly positively correlated with tumor shrinkage speed (p=0.0027), and a shrinkage speed of 0.64±0.12%/day was expected to enable a a tumor to be separated from its attached vessel.

Conclusion: Chemotherapy, especially by favorable combination with molecular targeting agents, even for resectable CLM appears to be acceptable and may lead to increased performance of radical surgical resection.