The optimal resection margin for HCC remains controversial yet has important implications for selection of surgical candidates and operative planning. This large retrospective series from Kansai Medical University compared procedures in which tumors were peeled from underlying major vascular structures (leaving essentially no margin and an exposed tumor surface) with procedures in which a more substantial margin was obtained. The finding that overall survival and the pattern of recurrence (including at the cut surface) was not adversely affected reinforces the greater importance that factors such as tumor biology, multifocality, cirrhosis, and medical comorbidities play in determining outcomes rather than resection margin per se. Current practice has shifted away from formal anatomic resection, instead emphasizing conservation and maximization of residual functional liver tissue. Margins even smaller than 1 cm may well be acceptable, though convincing clinical data one way or the other are lacking. Among the questions unanswered by the Kansai Medical University experience is whether the suitability of peeling an HCC tumor off of a major vascular structure is in itself a reflection of better tumor biology. The outcomes for lesions that happen to abut major vascular structures may differ depending on whether they display an expansile or an invasive growth pattern (leading to displacement or compression vs encircling or erosion into major vessels, respectively). Expansile-pattern HCC may exhibit more substantial pseudocapsule formation that allows apparent exposure of tumor surface without adversely affecting local recurrence. Information regarding true microscopic margin and the extent of tumor pseudocapsule formation is not provided. Given the ongoing uncertainties, the most prudent approach to resection of HCC should be to achieve a 1-cm margin while preserving maximal functional liver tissue. However, smaller margins are probably acceptable in order to remove those tumors that encroach upon major vascular structures by virtue of an expansile pattern of growth.
Matthews JB. Postoperative Outcomes in Patients With Hepatocellular Carcinomas Resected With Exposure of the Tumor Surface—Invited Critique. Arch Surg. 2007;142(7):603. doi:10.1001/archsurg.142.7.603