Positive Margins After Resection of Metastatic Colorectal Cancer in the Liver: Back to the Drawing Board?

Excerpt

The debate over the relevance of surgical margins in patients undergoing hepatic resection for metastatic colorectal cancer has gone on for decades. For many years a “1-cm margin” rule was recommended. Based on limited and now outdated information, patients with margins closer than 1 cm appeared to have significantly worse survival. As recently as 10 years ago, our group continued to find better outcomes associated with margins greater than 1 cm.1 More recently, most studies have found that beyond a 1-mm margin, there is no associated prolongation of survival. In fact, some groups have found that a positive margin does not matter at all, although these are typically reported in series where the margin positivity rate is as high as 50%.2 To add more fuel to the fire, we recently found that compared to a true positive margin (malignant cells at the actual margin), even negative margins <1 mm were associated with improved survival.3 One thing, however, is common throughout these myriad studies: in the context of multiple tumors, they all reported the surgical margin as that of the tumor with the closest margin. …