LAUSR

4262 Cancer November 1, 2018 assessing the adequacy of resection margin revision, but in a retrospective study clearly defining a group of patients with revised resection margins may suffice and local control data would indicate how (un)successful revisions were. The literature regarding the subject of resection margin revision does not indicate that re-excisions improve local control. This international collaborative study may in reality support the same conclusion, depending on the specifics of additional data outlined above. Additional information regarding resection margin re-excision may explain why in this report patients falling in the “close” margin category had outcomes that were worse or comparable to those of patients with “positive” resection margins. Rather than relying on a predetermined cutoff value of 5 mm to distinguish close from clear resection margins, the authors may want to reanalyze resection margin clearance as a continuous variable and offer a more relevant threshold reflective of the studied population. Fridman et al suggest that intraoperative resection margin assessment should be promoted to improve the achievement of adequate margins. This study was not designed to address such a hypothesis, and does not specify how often and by what method intraoperative resection margin assessment (macroscopic only, complete microscopic resection margin evaluation, or variations of the two) was performed. Some of the requirements for such a study have been described previously. Data with which to answer the question of whether the identification of a positive resection margin intraoperatively and its relocalization and re-excision improve patient outcomes were not presented within the study by Fridman et al. Although the authors appear to reference prior studies in support of routine intraoperative resection margin assessment, these reports actually raise questions regarding the clinical usefulness of intraoperative surgical resection margin assessment and highlight the challenges of adequate resection margin revision. Overall, it is difficult to go further and make sense of the data regarding adjuvant treatments in these gray areas, such as patients who have undergone resection margin revision. Prospective studies with standardized margin assessment and reporting clearly are needed to clarify important questions in this area.