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

Abstract

Background Controversy exists regarding the optimal negative margin width for ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and whole breast irradiation (WBRT). Methods A multidisciplinary consensus panel used a meta-analysis of margin width and ipsilateral breast tumor recurrence (IBTR) from a systematic review of 20 studies including 7883 patients and other published literature as the evidence base for consensus. Results Negative margins halve the risk of IBTR compared to positive margins defined as ink on DCIS. A 2 mm margin minimizes the risk of IBTR compared to smaller negative margins. More widely clear margins do not significantly decrease IBTR compared to 2 mm margins. Negative margins less than 2 mm alone are not an indication for mastectomy, and factors known to impact rates of IBTR should be considered in determining the need for re-excision. Conclusions The use of a 2 mm margin as the standard for an adequate margin in DCIS treated with WBRT is associated with low rates of IBTR and has the potential to decrease re-excision rates, improve cosmetic outcome, and decrease health care costs. Clinical judgment should be used in determining the need for further surgery in patients with negative margins < 2 mm.

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

“…Given the lack of consensus on what constitutes an adequate negative margin, we undertook a systematic review of the association between margins and LR in DCIS to determine the optimal minimum negative margin width and support the development of consensus guidelines 13 . Using study-level meta-analysis, the evidence on surgical margins in women with DCIS treated with BCS was systematically examined to: a) estimate the effect of microscopic margin status on LR; b) investigate the effect of various thresholds to define negative margins; and c) define a minimum negative margin distance to maximize local control.…”

Initial Community Hospital Performance of Radioactive Seed Localization for Breast Cancer Patients

“…The publication of consensus guidelines for stages I and II invasive cancer (Moran et al, 2014) as no tumor on ink and for DCIS (Morrow et al, 2016) as 3mm should facilitate comparisons between institutions for future patients. At our institution during the time the patients in our series were treated, we followed the NSABP definition and used no tumor on ink as being a negative margin for both invasive cancer and DCIS.…”

Intraoperative radiotherapy: Patient selection, management, and follow‐up

“…Fortunately, for patient receiving WBI, the margin width controversy has been largely settled by the publication of the Society of Surgical Oncology (SSO)‐ASTRO joint consensus guideline on surgical margins which defines a negative lumpectomy margin as “non‐transection” or “no ink on tumor” for invasive breast cancer and ≥2 mm for pure DCIS. In contrast, the ASTRO APBI Consensus Statement defines a negative lumpectomy margin as ≥2 mm for invasive breast cancer and “≥3 mm” for pure DCIS for patient receiving APBI …”