1330 How Does the Tumour-Free Margin Width After Breast-Conserving Surgery in Patients with Ductal Carcinoma in Situ (DCIS) Impact Local Recurrence Rates?

Abstract

Abstract Introduction In the UK, breast conserving surgery (BCS) has been indicated to completely excise ductal carcinoma in situ(DCIS) to negative margins for around 70% of diagnosed women. The tumour-free radial surgical margin width is an important marker for determining the local recurrence (LR). Setting the margin too wide will result in additional re-excision and too low may result in increased LR rates. This review investigates the different tumour-free margins and its effect on LR. Method A literature review was conducted using the Cochrane library and Pubmed database with key terms. Cohort studies of more than 100 participants with a five-year follow up in women over 18 were included. Results >2mm versus 0mm: LR was significantly reduced in DCIS from one very-low evidence retrospective cohort studies (N = 1,503). >2mm versus 1-2mm: Meaningful reduction in LR with DCIS was found in one very low-quality retrospective cohort study(N = 433). >2mm versus <1mm: Clinically meaningful reduction in LR for DCIS was found in very low-quality retrospective study (N = 466). >2mm versus 1-2mm: Meaningful reduction in LR with DCIS was found in one very low-quality retrospective cohort study(N = 433). Conclusions LR rates were reduced by further increasing the negative margin width in DCIS but only low-quality evidence was available to define these margins. This is an area for further research to enhance patient care and prevent increased LR.