Margins For Breast-Conserving Surgery With Whole-Breast Irradiation In Stages I And II Invasive Breast Cancer
Publication Date: March 1, 2014
Last Updated: March 14, 2022
Guideline Recommendations
What is the absolute increase in risk of IBTR with a positive margin? Can the use of radiation boost, systemic therapy, or favorable tumor biology mitigate this increased risk?
Positive margins, defined as ink on invasive cancer or DCIS, are associated with at least a 2-fold increase in IBTR. This increased risk in IBTR is not nullified by: delivery of a boost, delivery of systemic therapy (endocrine therapy, chemotherapy, biologic therapy), or favorable biology.
(Level of evidence: Meta-analysis and secondary data from prospective trials and retrospective studies)
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Do margin widths wider than no ink on tumor cells reduce the risk of IBTR?
Negative margins (no ink on tumor) optimize IBTR. Wider margins widths do not significantly lower this risk. The routine practice to obtain wider negative margin widths than ink on tumor is not indicated.
(Level of evidence: Meta-analysis and retrospective studies)
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What are the effects of endocrine or biologically targeted therapy or systemic chemotherapy on IBTR? Should a patient who is not receiving any systemic treatment have wider margin widths?
The rates of IBTR are reduced with the use of systemic therapy. In the uncommon circumstance of a patient not receiving adjuvant systemic therapy, there is no evidence suggesting that margins wider than no ink on tumor are needed.
(Level of evidence: Multiple randomized trials and meta-analysis)
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Should unfavorable biologic subtypes (such as triple-negative breast cancers) require wider margins (than no ink on tumor)?
Margins wider than no ink on tumor are not indicated based on biologic subtype.
(Level of evidence: Multiple retrospective studies)
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Should margin width be taken into consideration when determining WBRT delivery techniques?
The choice of whole-breast radiation delivery technique, fractionation, and boost dose should not be dependent on margin width.
(Level of evidence: Retrospective studies)
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Is the presence of LCIS at the margin an indication for re-excision? Do invasive lobular carcinomas require a wider margin (than no ink on tumor)? What is the significance of pleomorphic LCIS at the margin?
Wider negative margins than no ink on tumor are not indicated for invasive lobular cancer. Classic LCIS at the margin is not an indication for reexcision. The significance of pleomorphic LCIS at the margin is uncertain.
(Level of evidence: Retrospective studies)
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Should increased margin widths (wider than no ink on tumor) be considered for patients of young age (<40 years)?
Young age (40 years) is associated with both increased IBTR after BCT as well as increased local relapse on the chest wall after mastectomy and is also more frequently associated with adverse biologic and pathologic features. There is no evidence that increased margin width nullifies the increased risk of IBTR in young patients.
(Level of evidence: Secondary data from prospective randomized trials and retrospective studies)
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What is the significance of an EIC in the tumor specimen, and how does this pertain to margin width?
An EIC identifies patients who may have a large residual DCIS burden after lumpectomy. There is no evidence of an association between increased risk of IBTR when margins are negative.
(Level of evidence: Retrospective studies)
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Recommendation Grading
Overview
Title
Margins For Breast-Conserving Surgery With Whole-Breast Irradiation In Stages I And II Invasive Breast Cancer
Authoring Organizations
American Society for Radiation Oncology
Society of Surgical Oncology
Publication Month/Year
March 1, 2014
Last Updated Month/Year
June 26, 2023
Supplemental Implementation Tools
Document Type
Guideline
External Publication Status
Published
Country of Publication
US
Document Objectives
To convene a multidisciplinary panel of breast experts to examine the relationship between margin width and ipsilateral breast tumor recurrence (IBTR) and develop a guideline for defining adequate margins in the setting of breast conserving surgery and adjuvant radiation therapy.
Target Patient Population
Patients with Stage I/II breast cancer
Inclusion Criteria
Female, Male, Adolescent, Adult, Older adult
Health Care Settings
Ambulatory, Hospital, Operating and recovery room, Outpatient, Radiology services
Intended Users
Nurse, nurse practitioner, physician, physician assistant
Scope
Management, Treatment
Diseases/Conditions (MeSH)
D001941 - Breast Diseases, D013502 - General Surgery, D018787 - Radiation Oncology, D011827 - Radiation
Keywords
breast cancer, surgery, radiation therapy, Adjuvant Radiation Therapy, Breast Cancer