The impact of margins on outcome after hepatic resection for colorectal metastasis

OBJECTIVE: To analyze the impact of margin width on long-term outcome after hepatic resection for colorectal metastasis. SUMMARY BACKGROUND DATA: The optimal margin width and its influence on long-term outcome after hepatic resection for colorectal metastasis are unclear. METHODS: All patients undergoing hepatic resection for colorectal metastasis from 1991 to 2003 were identified, and the prognostic influence of margin width and other clinicopathologic factors were analyzed. RESULTS: A total of 1019 patients with a clear description of margin width were included. Analysis of margin width as a continuous variable suggested the following grouping: group I, involved (n = 112, 11%); group II, <1-10 mm (n = 563, 55%); and group III, >10 mm (n = 344, 33.7%). On univariate analysis, there was a statistically significant difference in median survival between all 3 groups: group II versus group I (42 vs. 30 months, P < 0.01) and group III versus group II (55 vs. 42 months, P < 0.01). Margin width >1 cm retained statistical significance (P < 0.01) on multivariate analysis after adjusting for established risk factors. After adjustment, survival in group III was significantly better than either group I or II (P < 0.01), but there was no difference between groups I and II (P = 0.31). CONCLUSIONS: This study provides evidence that margin width of >1 cm is optimal and is an independent predictor of survival after hepatic resection for colorectal metastasis. However, subcentimeter resections are also associated with favorable outcome and should not preclude patients from undergoing resection.