PurposeLocoregional recurrence after resection of colon cancer is increased when primary tumor margin is positive (<1 mm). Data is limited regarding the risk of locoregional recurrence with close margin (<1 mm) of histologic factors, such as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension. We hypothesized that close margin of these factors doesn't affect locoregional recurrence. MethodsA retrospective review of all colon cancer surgical resections for adenocarcinoma from 2007 to 2020 was performed. Inclusion criteria were specimens with a negative primary tumor margin but a close margin of adverse histologic factors, defined as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension within 1 mm of a mesenteric or circumferential margin. ResultsAmong 4435 pathology reports reviewed, 45 (1 %) of cases met inclusion criteria. Average follow-up was 38 months. The adverse histologic factor was identified as intranodal tumor in 24 (53 %) cases, intravascular tumor in 8 (17.8 %), tumor deposits in 5 (11.1 %), and more than one pathologic feature in 6 (13.3 %). There were 9 (20 %) recurrences; 6 (13 %) had distant recurrences only, 2 (4 %) patients had locoregional recurrences only, and 1 (2 %) patient had both locoregional and distant recurrence. The adverse histologic factor in these three patients was intravascular in two and both intravascular and intranodal in one. ConclusionBased on our results, we do not have evidence that the presence of intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension within 1 mm of a mesenteric or circumferential margin is associated with increased risk of locoregional recurrence.
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