DCIS (ductal carcinoma in situ) is a non-invasive breast cancer.
In DCIS, the abnormal cells are contained in the milk ducts (canals that carry milk from the lobules to the nipple openings during breastfeeding). It is called “in situ” (which means "in place") because the cells have not left the milk ducts to invade nearby breast tissue.
DCIS is also called intraductal (within the milk ducts) carcinoma. You may also hear the terms “pre-invasive” or “pre-cancerous” to describe DCIS.
DCIS can be found alone or with invasive breast cancer.
If DCIS is diagnosed with invasive breast cancer, treatment and prognosis are based on the invasive breast cancer (not the DCIS).
Learn about treatment for early breast cancer.
DCIS is non-invasive, but without treatment, the abnormal cells could turn into invasive cancer over time.
Left untreated, about 40-50 percent of DCIS cases may progress to invasive breast cancer . (These numbers are estimates.) Higher grade DCIS may be more likely than lower grade DCIS to turn into invasive cancer if left untreated.
At this time, health care providers cannot predict which cases of DCIS will progress to invasive breast cancer and which will not. Because DCIS might turn into invasive breast cancer, almost every case of DCIS is treated.
Surgery (with or without radiation therapy) is recommended for the treatment of DCIS. After surgery and radiation therapy, some women may take hormone therapy.
Learn more about treatments for DCIS.
Learn about the risk of invasive breast cancer after treatment for DCIS.
Although the exact treatment for DCIS varies from person to person, guidelines help ensure quality care. These guidelines are based on the latest research and the consensus of experts.
The National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO) are two respected organizations that regularly update and post their guidelines online. The National Cancer Institute (NCI) also has overviews of treatment options.
With treatment, prognosis for DCIS is usually excellent.
Surgery is the first step in treating DCIS. It removes the abnormal tissue in the breast. Depending on how far the DCIS has spread within the milk ducts, surgery can be either mastectomy or lumpectomy.
Overall survival is the same for women with DCIS who have mastectomy and those who have lumpectomy (with or without radiation therapy) .
In the U.S., most women with DCIS choose lumpectomy followed by radiation therapy .
Learn more about mastectomy and lumpectomy.
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 [2-8]:
Select women with smaller, lower grade DCIS and clean surgical margins, may be able to have lumpectomy without radiation therapy [2,9].
Overall survival is the same for women with DCIS who have lumpectomy with or without radiation therapy [2,4].
Learn more about radiation therapy.
For a summary of research studies on lumpectomy plus radiation therapy in the treatment of DCIS, visit the Breast Cancer Research Studies section.
A pathologist determines the hormone receptor status by testing the DCIS tumor tissue removed during a biopsy.
Hormone receptor-positive DCIS may benefit from treatment with hormone therapy (tamoxifen or an aromatase inhibitor) [2,6,12].
Learn about hormone receptor status and invasive breast cancer.
Hormone therapy is not usually recommended for women who have a mastectomy for DCIS. These women have an excellent prognosis with a very low risk of DCIS recurrence or developing breast cancer in the opposite breast, so the benefit of tamoxifen is likely very small.
The National Comprehensive Cancer Network (NCCN) recommends women who are treated with lumpectomy plus radiation therapy for estrogen receptor-positive DCIS consider taking hormone therapy (tamoxifen or an aromatase inhibitor) for 5 years .
Studies have shown hormone therapy can lower the risk of [10-14]:
Learn more about tamoxifen.
Learn more about aromatase inhibitors.
Learn more about factors that affect treatment options.
Learn more about emerging areas in the treatment of DCIS.
For a summary of research studies on tamoxifen as a treatment for DCIS, visit the Breast Cancer Research Studies section.
After treatment for DCIS there is still a small risk of:
These risks are higher with lumpectomy plus radiation therapy than with mastectomy .
However, overall survival is the same after either treatment . With close follow-up, invasive breast cancer is usually caught early and can be treated successfully.
In 2013, the Health and Medicine Division of the National Academy of Sciences (formerly the Institutes of Medicine) released a set of recommendations (below) on improving cancer care in the U.S. The report, Delivering High-Quality Cancer Care: Charting a New Course for a System in Crisis recommended improvements to fix shortcomings that add cost and burden to cancer care. Susan G. Komen was one of 13 organizations that sponsored this study.
The report identified key ways to improve quality of care:
Read the full report.
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*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date at this time.
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Ductal Carcinoma in Situ
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