The Association of Surgical Margins and Local Recurrence in Women with Ductal Carcinoma In Situ Treated with Breast-Conserving Therapy: A Meta-Analysis

Abstract

Purpose There is no consensus on adequate negative margins in breast-conserving surgery (BCS) for ductal carcinoma in-situ (DCIS). We systematically review the evidence on margins in BCS for DCIS. Methods Study-level meta-analysis of local recurrence (LR), microscopic margin status and threshold distance for negative margins. LR proportion was modelled 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 7,883), 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 1mm, ORs for 2mm (0.51), 3 or 5mm (0.42) and 10mm (0.60) showed comparable significant reductions in the odds of LR. In the network analysis, ORs relative to positive margins for 2mm (0.32), 3mm (0.30) and 10mm (0.32) showed similar reductions in the odds of LR that were greater than for >0 or 1mm (0.45). There was weak evidence of lower odds at 2mm compared to >0 or 1mm (Relative OR=0.72, 95% credible interval [CrI] 0.47-1.08), and no evidence of a difference between 2mm and 10mm (Relative OR=0.99, 95% CrI 0.61-1.64). Adjustment for covariates, and analyses based only on studies using whole-breast radiotherapy, did not change findings. Conclusion Negative margins in BCS for DCIS reduce the odds of LR; however, minimum margins distances above 2mm are not significantly associated with further reduced odds of LR in women receiving radiation.

Society of Surgical Oncology–American Society for Radiation Oncology–American Society of Clinical Oncology Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation in Ductal Carcinoma in Situ

“…15 The median proportion of patients receiving WBRT was 100% (interquartile range [IQR] 53.3–100.0%), and the median proportion receiving endocrine therapy was 20.8% (IQR 0.0–31.4%). The median follow-up was 78.3 months, and the median incidence of IBTR was 8.3% (IQR 5.0–11.9%).…”

“…15 Briefly, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Institute of Medicine guidelines, EMBASE, MEDLINE, PREMEDLINE, and evidence-based medicine databases were searched in October 2014 for eligible studies. A summary providing details of the methodology and statistical approaches is provided in the Appendix.…”

“…16 All reported odds ratio (ORs) were adjusted for study-specific median follow-up time (to account for the inherent increased risk of IBTR with longer follow-up) and are reported relative to positive (or positive/close) margins, or to a minimal negative margin (no ink on tumor or margin > 1 mm). 15 …”

“…18 In the meta-analysis of Marinovich et al using the Bayesian analytic approach, similar results were obtained. 15 After adjustment for study-level follow-up, patients with negative margins were significantly less likely to experience IBTR than patients with positive margins (OR 0.45, 95% credible interval [CrI] 0.30–0.62). Similar findings were observed in the frequentist analysis which necessitated combining positive and close margins (OR 0.53, 95% confidence interval (CI) 0.45–0.62; p < .001).…”

Diagnosis and Treatment of Breast Cancer in Situ. Russian Association of Oncological Mammology Clinical Guidelines (Project)

“…[7], выполнена оценка влияния ширины края ре-зекции (0,1 мм против 2 мм, 3 или 5 мм и 10 мм) на про-гноз. В исследовании участвовали 7883 пациента со средним периодом наблюдения 6,5 года.…”