The significance and clinical factors associated with a subcentimeter resection of colorectal liver metastases

Background: Prognosis after resection of colorectal liver metastases is influenced by various factors. A positive margin of resection (MOR) has been shown to adversely influence prognosis. Although a 1-cm MOR has been accepted as adequate, the data to support this guideline are sparse. Methods: Our hepatobiliary database was queried for patients who underwent liver resection for colorectal metastases between January 1992 and July 2003. All patients were divided into three groups: MOR <.5 cut (group A), .5 to 1 cm (group B), and > 1 cut (group C). Operative reports from each hepatic resection were analyzed to determine local factors that may have contributed to a subcentimeter MOR. Results: A total of 112 patients (67 men and 45 women) underwent liver resection for colorectal metastases with negative margins. Fifty-three patients were in group A, 26 patients were in group 13, and 33 patients were in group C. Group C demonstrated decreased local recurrence (LR; P=.003), distant recurrence (DR; P=.008), and disease-free recurrence (P=.002). A significant difference in the overall time to LR (P=.003), time to DR (P=.003), and disease-free survival (P=.002) was also demonstrated. Factors associated with a subcentimeter MOR included nonanatomical resection (P=.043), proximity to a major vessel (P=.003), and central location (P=.002). Conclusions: A <1-cm resection for colorectal liver metastases is associated with increased LR and DR, as well as decreased disease-free survival. When a nonanatomical resection is performed, a MOR > 1 cm should be attempted, because an adequate margin is often underestimated. Considerations should be made for extended resections when tumors are centrally located or near major vessels.