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Medline ® Abstract for Reference 56

of 'Breast conserving therapy'

The Association of Surgical Margins and Local Recurrence in Women with Ductal Carcinoma In Situ Treated with Breast-Conserving Therapy: A Meta-Analysis.
Marinovich ML, Azizi L, Macaskill P, Irwig L, Morrow M, Solin LJ, Houssami N
Ann Surg Oncol. 2016;23(12):3811. Epub 2016 Aug 15.
PURPOSE: There is no consensus on adequate negative margins in breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS). We systematically reviewed the evidence on margins in BCS for DCIS.
METHODS: A study-level meta-analysis of local recurrence (LR), microscopic margin status and threshold distance for negative margins. LR proportion was modeled using random-effects logistic meta-regression (frequentist) and network meta-analysis (Bayesian) that allows for multiple margin distances per study, adjusting for follow-up time.
RESULTS: Based on 20 studies (LR: 865 of 7883), odds of LR were associated with margin status [logistic: odds ratio (OR) 0.53 for negative vs. positive/close (p < 0.001); network: OR 0.45 for negative vs. positive]. In logistic meta-regression, relative to>0 or 1 mm, ORs for 2 mm (0.51), 3 or 5 mm (0.42) and 10 mm (0.60) showed comparable significant reductions in the odds ofLR. In the network analysis, ORs relative to positive margins for 2 (0.32), 3 (0.30) and 10 mm (0.32) showed similar reductions in the odds of LR that were greater than for>0 or 1 mm (0.45). There was weak evidence of lower odds at 2 mm compared with>0 or 1 mm [relative OR (ROR) 0.72, 95 % credible interval (CrI) 0.47-1.08], and no evidence of a difference between 2 and 10 mm (ROR 0.99, 95 % CrI 0.61-1.64). Adjustment for covariates, and analyses based only on studies using whole-breast radiotherapy, did not change the findings.
CONCLUSION: Negative margins in BCS for DCIS reduce the odds of LR; however, minimum margin distances above 2 mm are not significantly associated with further reduced odds of LR in women receiving radiation.
Screening and Test Evaluation Program (STEP), Sydney School of Public Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia. luke.marinovich@sydney.edu.au.