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’s called “in situ” (which means "in place") because the cells have not left the milk ducts to invade nearby breast tissue.
Image source: National Cancer Institute (http://www.cancer.gov)
DCIS is also called intraductal (within the milk ducts) carcinoma. You may hear the terms “pre-invasive” or “pre-cancerous” to describe DCIS.
DCIS is treated to try to prevent the development of invasive breast cancer.
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 progress to invasive cancer over time.
Left untreated, it's estimated 40-50 percent of DCIS cases may progress to invasive breast cancer .
Health care providers cannot predict which cases of DCIS will progress to invasive breast cancer and which will not. Because DCIS might progress to invasive breast cancer, almost all cases of DCIS are treated.
Surgery (with or without radiation therapy) is recommended to treat DCIS. After surgery and radiation therapy, some people take hormone therapy.
Learn more about treatments for DCIS.
Learn about the risk of invasive breast cancer after treatment for DCIS.
Learn more about emerging areas in the treatment of DCIS.
Although the exact treatment for DCIS varies from person to person, guidelines help ensure high-quality care. These guidelines are based on the latest research and agreement among experts.
The National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO) are respected organizations that regularly review and update their guidelines.
In addition, the National Cancer Institute (NCI) provides treatment overviews.
With treatment, prognosis (chance of survival) for DCIS is usually excellent.
Surgery is the first step to treat DCIS. It removes the abnormal tissue from the breast.
Depending on how far the DCIS has spread within the milk ducts, surgery can be mastectomy or lumpectomy.
If DCIS is spread throughout the ducts, affecting a large part of the breast, a total (simple) mastectomy will be done. With a total mastectomy, the surgeon removes the entire breast and possibly some lymph nodes, but no other tissue.
If there's little spread of DCIS within the ducts, a choice can be made between mastectomy or lumpectomy.
With lumpectomy, the surgeon removes only the abnormal tissue in the breast. The rest of the breast is left intact. Lymph nodes are not usually removed with lumpectomy for DCIS.
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 are treated with lumpectomy followed by radiation therapy .
A sentinel node biopsy is a procedure used to check whether or not invasive breast cancer has spread to the lymph nodes in the underarm area (axillary nodes). The surgeon will remove 1-5 nodes.
Having a sentinel node biopsy during a mastectomy helps some people with DCIS avoid an axillary dissection. Once a mastectomy has been done, a person can't have a sentinel node biopsy.
If it turns out there’s invasive breast cancer (along with DCIS) in the tissue removed during the mastectomy, the sentinel node biopsy will have already been done.
If a sentinel node biopsy wasn't done and invasive breast cancer is found, an axillary dissection may be needed. An axillary dissection removes more axillary lymph nodes than a sentinel node biopsy. Because it disrupts more of the normal tissue in the underarm area, axillary dissection is more likely to affect arm function and cause lymphedema.
So, even though a sentinel node biopsy may not be needed with DCIS, most people who have a mastectomy for DCIS will have a sentinel node biopsy done at the same time.
Radiation therapy is rarely given to women treated with mastectomy for DCIS.
Lumpectomy for DCIS is usually followed by whole breast radiation therapy to lower the risk of [2-9]:
A meta-analysis that combined the results of 4 randomized clinical trials showed lumpectomy plus whole breast radiation therapy reduced the risk of invasive breast cancer after DCIS (in the same breast treated for DCIS) by half compared to lumpectomy alone .
Overall survival is the same for women with DCIS who have lumpectomy with or without whole breast radiation therapy [2-4]. So, questions remain about the need for all women to get radiation therapy after lumpectomy for DCIS.
Some women with small, low grade DCIS and clean surgical margins have a low risk of recurrence after lumpectomy. Some of these women may choose to have accelerated partial breast radiation therapy or avoid radiation therapy altogether [2,9-10].
For a summary of research studies on lumpectomy plus whole breast radiation therapy in the treatment of DCIS, visit the Breast Cancer Research Studies section.
A pathologist determines the hormone receptor status of the DCIS by testing the tissue removed during a biopsy.
Hormone receptor-positive DCIS may benefit from hormone therapy (tamoxifen or an aromatase inhibitor) [2,6,11-15].
Learn about hormone receptor status and invasive breast cancer.
Hormone therapy isn’t recommended for women who have a mastectomy for DCIS because the benefit would likely be very small (and would mostly affect the risk of cancer in the opposite breast).
Women who have a mastectomy for DCIS have an excellent prognosis with a very low risk of DCIS recurrence or developing breast cancer in the opposite breast.
The National Comprehensive Cancer Network (NCCN) recommends women who are treated with lumpectomy for estrogen receptor-positive DCIS consider taking hormone therapy (tamoxifen or an aromatase inhibitor) for 5 years .
In women treated with lumpectomy and radiation therapy for DCIS, studies have shown hormone therapy can lower the risk of [2-9]:
Learn more about factors that affect treatment options.
Learn 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's 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 .
Higher grade DCIS appears more likely than lower grade DCIS to progress to invasive cancer after treatment (surgery, with or without radiation therapy) .
With close follow-up, invasive breast cancer is usually caught early and can be treated effectively.
Learn more about talking with your health care provider.
If you’ve been diagnosed with DCIS, Susan G. Komen® has Questions to Ask Your Doctor resources that may be helpful. For example, we have a Questions to Ask Your Doctor About Breast Cancer Surgery resource and a Questions to Ask Your Doctor About Radiation Therapy and Side Effects resource.
You can download and print these resources and take them with you to your next doctor appointment. There’s plenty of space to write down the answers to these questions, which you can refer to later.
There are other Questions to Ask Your Doctor resources on many different breast cancer topics you may wish to download. They are a nice tool for people recently diagnosed with breast cancer, who may be too overwhelmed to know where to begin to gather information.
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 ways 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.
Breast Cancer 101 - Treatment for Stage 0
Ductal Carcinoma in Situ
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