This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.
Introduction: Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer.
Without treatment, DCIS can progress to invasive breast cancer over time. So, all cases of DCIS are treated.
Treatment involves surgery, with or without radiation therapy. Some women may also take the hormone therapy drug tamoxifen.
Radiation therapy is not given to women who are treated with mastectomy for DCIS.
Lumpectomy for DCIS is usually followed by radiation therapy to lower the risk of:
A meta-analysis that combined the results of 4 randomized clinical trials showed lumpectomy plus radiation therapy lowered the risk of invasive breast cancer after DCIS (in the same breast as the DCIS) by 50 percent compared to lumpectomy alone .
Overall survival appears similar for women with DCIS who have lumpectomy with or without radiation therapy [1-2].
Learn more about treatment for DCIS.
Learn about the strengths and weaknesses of different types of studies.
Study selection criteria: Randomized clinical trials with at least 500 participants and 5 or more years of follow-up and meta-analyses.
Study Population (number of participants)
Percent of Women who Developed Invasive Breast Cancer*
Overall Survival (for length of follow-up)
Radiation Therapyafter Lumpectomy
NoRadiation Therapyafter Lumpectomy
No RadiationTherapyafter Lumpectomy
Randomized clinical trials
UK, Australia, New Zealand (UK/ANZ) DCIS Trial 
Swedish Breast Cancer Group 
European Organization for Research and Treatment of Cancer (EORTC) 
National Surgical Adjuvant Breast and Bowel Project (NSABP) B-17 
Radiation Therapy Oncology Group 
Less than 1%
Cochrane Collaboration 
Stuart et al. 
* Invasive breast cancer in the same breast treated for DCIS
† Breast cancer survival (not overall survival)
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