New Guidelines for Surgical Margins After DCIS Breast Cancer Interview with:

Monica Morrow, MD, FACS Chief, Breast Service, Department of Surgery Anne Burnett Windfohr Chair of Clinical Oncology

Dr. Monica Morrow

Monica Morrow, MD, FACS
Chief, Breast Service
Department of Surgery
Anne Burnett Windfohr Chair of Clinical Oncology
Memorial Sloan-Kettering Cancer Center What is the background for this study?

Response: DCIS, ductal carcinoma in situ, intraductal cancer or Stage 0 cancer refers to what some people call the earliest form of cancer we can find and others term “precancerous”. This difference in terms is due to the fact that DCIS lacks the ability to spread to other parts of the body, a fundamental characteristic of cancer. The goal of treatment in DCIS is to prevent progression to invasive cancer which has the ability to spread. DCIS accounted for only 2-3 % of breast cancers seen in the pre-screening mammography era, but it comprises 25-30% of the malignancies detected in screening mammography programs.

For this reason it is uncommon in women under age 40, and more commonly seen in women over 50 years of age. Approximately 70% of the women in the US diagnosed with DCIS are treated with lumpectomy (removal of the DCIS and a margin of surrounding normal breast tissue), and additional surgeries to obtain clear, or more widely clear, margins are done in approximately 30% of women.

For this reason, the Society of Surgical Oncology, the American Society for Therapeutic Radiation Oncology, and the American Society of Clinical Oncology undertook the development of an evidence based guideline to determine the optimal clear margin for women with DCIS treated with lumpectomy and whole breast radiotherapy. What are the main findings?

Response: Key findings of the guideline were that a clear margin of 2mm optimally reduced the risk of cancer recurring in the breast, but more widely clear margins did not further improve outcomes.

This finding has the potential to save many women additional surgery and its associated anxiety, as well as to decrease the likelihood of cosmetic deformity of the breast, and will reduce health care costs. For women with clear margins

However, the guideline emphasizes that a clear margin less than 2mm, by itself, should not be considered an indication to do a mastectomy. The finding that margins larger than 2mm do not reduce the risk of DCIS recurring is part of a growing body of evidence that indicates that biology, rather than the extent of the surgical procedure, is a major determinant of outcome for both DCIS and invasive cancer. Thank you for your contribution to the community.


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
Monica Morrow, Kimberly J. Van Zee, Lawrence J. Solin, Nehmat Houssami,Mariana Chavez-MacGregor, Jay R. Harris, Janet Horton, Shelley Hwang,Peggy L. Johnson, M. Luke Marinovich, Stuart J. Schnitt, Irene Wapnir, and Meena S. Moran
JCO published online on August 15, 2016; DOI:10.1200/JCO.2016.68.3573

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Last Updated on August 18, 2016 by Marie Benz MD FAAD