Frequency of positive margins and predictors in breast-conserving surgery in developing countries

Abstract

Achieving negative surgical margins in breast-conserving surgery (BCS) is crucial due to the risks linked to positive margins, such as the need for reoperation and elevated local recurrence rates. Limited data exist about positive margins after BCS in developing countries, including Iran, and this study aims to close this gap by assessing the rates of positive margins in BCS and the factors that affect it. This retrospective study investigated breast cancer patients at Tehran University of Medical Sciences from 2003 to 2024. It included female patients who underwent BCS and had complete data available. The rate of positive margins in histological assessment of surgical specimens and its relationship with various tumor and patient factors were explored using univariate and multivariate logistic model analyses. A total of 2,585 patients underwent BCS, with a median age of 49 and a mean tumor size of 27 mm. Free surgical margins were found in 91.4% of cases, while 8.6% exhibited involved margins, these underwent re-excision of the involved margin. A significant association was observed between younger patient age, tumor size, and lymphovascular invasion, with margin involvement. This study found a lower margin positivity rate in BCS than reported in the great part of the present literature, it also identified preoperative clinical and pathological factors linked to margin involvement, allowing for better risk prediction and potential surgical adjustments.