Background: Preoperative chemotherapy has become more common in the management of multiple resectable colorectal liver metastases; however, the benefit is unclear. This study examined clinical outcomes following liver resection for multiple colorectal liver metastases with the surgery up-front approach.
Methods: Data collected prospectively over a 16-year period for 736 patients who underwent hepatic resection at two different centers were reviewed. Patients were divided into three groups depending on the number of tumors as follows: group A, between one and three tumors (n = 493); group B, between four and seven tumors (n = 141); and group C, eight or more tumors (n = 102).
Results: The 5-year overall and recurrence-free survival rates were 51 and 21 %, respectively, for the entire patient cohort, 56 and 29 % in group A, 41 and 12 % in group B, and 33 and 1.7 % in group C. Multivariate analysis showed that decreased survival was associated with positive lymph node metastasis of the primary tumor, the presence of extrahepatic tumors, a maximum liver tumor size >5 cm, and tumor exposure during liver resection.
Conclusions: In patients with multiple liver metastases, the number of liver metastases has less impact on the prognosis than other prognostic factors. Complete resection with repeat metastasectomy offers a chance of cure even in patients with numerous colorectal liver metastases (i.e., those with eight or more nodules). A further prospective study is necessary to clarify the optimal setting of preoperative chemotherapy.