Tumor margins that lead to reoperation in breast cancer: A retrospective register study of 4,489 patients

Abstract

<p>Background and Objectives <br></p><p>Optimal margins for ductal carcinoma in situ (DCIS) remain controversial in breast-conserving surgery (BCS) and mastectomy. We examine the association of positive margins, reoperations, DCIS and age. <br></p><p>Methods<br></p><p> A retrospective study of histopathological reports (4489 patients). Margin positivity was defined as ink on tumor for invasive carcinoma. For DCIS, we applied 2 mm anterior and side margin thresholds, and ink on tumor in the posterior margin. <br></p><p>Results <br></p><p>The incidence of positive side margins was 20% in BCS and 5% in mastectomies (<em>p</em> < 0.001). Of these patients, 68% and 14% underwent a reoperation (<em>p</em> < 0.001). After a positive side margin in BCS, the reoperation rates according to age groups were 74% (<49), 69% (50-64), 68% (65-79), and 42% (80+) (<em>p</em> = 0.013). Of BCS patients with invasive carcinoma in the side margin, 73% were reoperated on. A reoperation was performed in 70% of patients with a close (<= 1 mm) DCIS side margin, compared to 43% with a wider (1.1-2 mm) margin (<em>p</em> = 0.002). The reoperation rates were 55% in invasive carcinoma with close DCIS, 66% in close extensive intraductal component (EIC), and 83% in close pure DCIS (<em>p</em> < 0.001). <br></p><p>Conclusions <br></p><p>Individual assessment as opposed to rigid adherence to guidelines was used in the decision on reoperation.</p>