Earl Abraham1, David Roshan1,2, Bryan Tran1, Susannah Graham1, Christopher Lehane1, James Wykes1,2, Peter Campbell1, Ardalan Ebrahimi1,2,3,4,5. 1. Department of Head and Neck Surgery, Liverpool Hospital, Liverpool, New South Wales, Australia. 2. Department of Medicine, University of New South Wales, Sydney, New South Wales, Australia. 3. Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia. 4. Medical School, College of Health and Medicine, Australian National University, Canberra, Australia. 5. Department of Head and Neck Surgery, The Canberra Hospital, Canberra, Australia.
Abstract
BACKGROUND: Although microscopic positive margins appear to have no independent prognostic impact in papillary thyroid cancer (PTC), this may not be the case in pT4a tumors. METHODS: Retrospective analysis of 610 patients with PTC, 39 with pT4a tumors, to determine if microscopic positive margins impact disease-free survival (DFS) in pT4a PTC. RESULTS: On univariate analysis, microscopic positive margins were not associated with reduced DFS in patients with no extrathyroidal extension (ETE) (hazard ratio [HR], 1.7; P = 0.32), microscopic ETE (HR, 1.6; P = 0.36), or macroscopic ETE limited to strap muscles (HR, 1.2; P = 0.87). In contrast, microscopic positive margins were associated with reduced DFS in T4a disease (HR, 4.1; P = 0.04). Disease recurrence was nodal, distant, or biochemical, and did not occur directly at the site of positive margins. CONCLUSION: Although microscopic positive margins do not influence DFS in the majority of patients with PTC, they are associated with a fourfold increased risk of recurrence in pT4a disease.
BACKGROUND: Although microscopic positive margins appear to have no independent prognostic impact in papillary thyroid cancer (PTC), this may not be the case in pT4a tumors. METHODS: Retrospective analysis of 610 patients with PTC, 39 with pT4a tumors, to determine if microscopic positive margins impact disease-free survival (DFS) in pT4a PTC. RESULTS: On univariate analysis, microscopic positive margins were not associated with reduced DFS in patients with no extrathyroidal extension (ETE) (hazard ratio [HR], 1.7; P = 0.32), microscopic ETE (HR, 1.6; P = 0.36), or macroscopic ETE limited to strap muscles (HR, 1.2; P = 0.87). In contrast, microscopic positive margins were associated with reduced DFS in T4a disease (HR, 4.1; P = 0.04). Disease recurrence was nodal, distant, or biochemical, and did not occur directly at the site of positive margins. CONCLUSION: Although microscopic positive margins do not influence DFS in the majority of patients with PTC, they are associated with a fourfold increased risk of recurrence in pT4a disease.