Management of colorectal liver metastasis : better decision and improving surgical outcome

Abstract

Liver resection is the only potential curative therapy for patients with resectable colorectal liver metastasis (CRLM). Over the past years, the oncological outcomes of CRLM have improved drastically due to evolvement of surgical management and development of modern chemotherapies. However, a number of issues in the management of CRLM remain controversial while the management itself is becoming an art. This thesis examined the following issues in CRLM management: long-term survival, anemia, body mass index, staged versus simultaneous resection, anatomical versus non-anatomical resection, the anterior approach to resection, and the relationship between resection margin and chemotherapy. Most cancer-specific deaths occur in the first 5 years after surgery. The study on long-term survival had a follow-up period of 10 years to ensure that late recurrences were taken into account so as to demonstrate the true curative potential of resection. Patients with more tumor nodules and bilobar involvement had worse survival, especially in 10-year survivors. Adjuvant chemotherapy would help to improve overall survival. Anemia is common in cancer patients. The study on anemia investigated its effect on the short- and long-term outcomes of resection of CRLM. Anemic patients had more major complications and inferior survival (disease-free and overall). Treatment of anemia before operation could improve the outcomes of operation. Adverse surgical and oncological outcomes have been seen in underweight, overweight and obese CRLM patients. The study on body mass index found that patients who had a high body mass index, especially those with synchronous CRLM, had worse postoperative outcome. Staged resection is therefore recommended for these patients. Surgical strategy in CRLM is controversial. Some surgeons suggested staged resection as a ‘test of time’ approach, whereas some suggested simultaneous resection to avoid loss of chance for surgery. The study on this topic showed that staged resection in general resulted in better survival outcomes than simultaneous resection did. The study on anatomical versus non-anatomical resection found no difference between the two approaches in long-term oncological outcomes, but anatomical resection might entail a more eventful postoperative course. Hence, non-anatomical resection with adequate resection margin should always be considered. The study on the anterior approach compared it with the conventional approach and saw no difference between them in surgical outcomes, but the anterior approach allowed better mobilization and easier removal of large tumors once the liver was opened up. Resection margin width has become less important with modern chemotherapy. The study on chemotherapy and margin status identified that 1.09 cm is the optimal margin width, which, together with the use of perioperative chemotherapy, is important in achievement of favorable overall survival. In conclusion, the findings in this thesis provide useful information to help with perioperative decision and surgical management in the management of CRLM.