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

PurposeControversy exists regarding the optimal negative margin width for ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and whole-breast irradiation.MethodsA multidisciplinary consensus panel used a meta-analysis of margin width and ipsilateral breast tumor recurrence (IBTR) from a systematic review of 20 studies including 7,883 patients and other published literature as the evidence base for consensus.ResultsNegative margins halve the risk of IBTR compared with positive margins defined as ink on DCIS. A 2-mm margin minimizes the risk of IBTR compared with smaller negative margins. More widely clear margins do not significantly decrease IBTR compared with 2-mm margins. Negative margins narrower than 2 mm alone are not an indication for mastectomy, and factors known to affect rates of IBTR should be considered in determining the need for re-excision.ConclusionUse of a 2-mm margin as the standard for an adequate margin in DCIS treated with whole-breast irradiation is associated with lower rates of IBTR and has the potential to decrease re-excision rates, improve cosmetic outcomes, and decrease health care costs. Clinical judgment should be used in determining the need for further surgery in patients with negative margins narrower than 2 mm.

Wherein the Authors Attempt to Minimize the Confusion Generated by Their Study “Breast Cancer Mortality after a Diagnosis of Ductal Carcinoma In Situ” by Several Commentators Who Disagree with Them and a Few Who Don’t: A Qualitative Study

“…Nevertheless, many commentators misinterpreted the finding of low mortality to infer either that dcis is a precursor, and not a cancer [15][16][17][18] ; that dcis is overdiagnosed and does not need to be treated (that is, "watch and wait") [19][20][21][22][23][24][25][26][27][28][29] ; or that dcis is overtreated (that is, omit radiotherapy) [30][31][32][33][34] . Most troubling from our point of view was that several commentators interpreted the finding that the increased risk of death from breast cancer in dcis patients who developed an ipsilateral invasive recurrence justified efforts to prevent the invasive ipsilateral recurrence as a life-saving measure [35][36][37][38][39][40][41][42][43] . Only 5 of the 50 articles referenced our paper in the intended context: that is, that dcis can metastasize, or that breast cancer is a systemic disease that disseminates and metastasizes early [44][45][46][47][48] .…”

Paradigm Shift From Halstedian Radical Mastectomy to Personalized Medicine

“…And, most breast surgeons do not perform axillary lymph node dissection even in the presence of 1 or two positive sentinel lymph node(s) due to the results of ACOSOG Z0011 trial (19). New consensus conferences on surgical margins in patients with invasive and ductal carcinoma in situ (DCIS) recommend no-ink on tumour for invasive, and 2 mm for DCIS as clear surgical margin (20)(21). This new margin status has been increasing the breast conserving surgery rate and decreasing re-excision(s), thereby resulting in poor cosmetic results.…”

Radiation Therapy Following Breast Conserving Surgery for Ductal Carcinoma in situ: Yes or No?

“…(31) The Society of Surgical Oncology (SSO), American Society for Radiation Oncology (ASTRO) and the American Society of Clinical Oncology (ASCO) developed a Consensus Guideline on margins for BCS with wholebreast radiotherapy (WBRT) in DCIS. (32) The guideline was based on the results of a meta-analysis including 20 studies, 7,883 DCIS patients with known margins status and 865 ipsilateral breast tumor recurrences (IBTR).…”