SSO/ASTRO Guideline on Margins for Breast-Conserving Surgery (BCS) with Whole-Breast Irradiation (WBI) in Stages I and II Invasive Breast Cancer

Published: March 2014

Read Full-Text Guideline

This collaborative guideline considers several questions related to defining margins for patients who have reached breast-conserving surgery and WBI. It delineates when margins are positive and the necessary width to consider the margin negative. It also addresses the interaction between margin width and systemic therapy; biologic subtype; radiation therapy technique, fractionation and boost; invasive lobular carcinoma or lobular carcinoma in situ; and young age. 

Developed in collaboration with:

• American Society for Radiation Oncology
• Society of Surgical Oncology

Endorsed by:​

• American Society of Breast Surgeons
• American Society of Clinical Oncology

Key Points:

• Risk of ipsilateral breast tumor recurrence (IBTR)
• IBTR rate
• Margin width
• Local failure

Resources: 

Breast Cancer Refresher - 2017 (CME)
Timing of RT and Chemo after BCS for Node-Positive Breast Cancer (CME)
Patient Brochure