We teach you about DCIS and how it is treated. This pre-cancerous problem is also a risk factor for developing invasive cancer and is linked to the BRCA genetic mutation.


Questions for your Breast Surgeon and Medical Oncologist:

  • Is DCIS cancer or a precancerous growth?
  • What exactly is the threat to my health from DCIS?
  • Are both surgery and radiation always needed for DCIS?
  • May I have a copy of my pathology reports?
  • Do I qualify for genetic testing if I have DCIS?

Will DCIS turn into an invasive cancer if not treated?

Ductal Carcinoma In-Situ (DCIS) refers to breast cells that are growing abnormally in an area of the breast but have not yet evolved to the point where they are considered “invasive breast cancer” and can spread beyond the breast to other parts of the body. Even the medical field is unsure whether to call it “non-invasive” breast cancer or a “precancerous” problem. By definition, DCIS is considered a Stage O breast cancer.


Important facts if you have DCIS:

  • If left untreated, it can evolve into an invasive breast cancer
  • You have a slightly higher lifetime risk of forming a new cancer in either breast in the future
  • You may now qualify for BRCA genetic testing.


How is DCIS different from invasive cancer?

Invasive Breast Cancer can threaten your life because it may have the capacity to spread (metastasize) to other organs of the body. DCIS does not yet have this ability to spread, but it might if it evolves into invasive breast cancer in the future. So we treat DCIS very seriously in order to lessen the risk of it developing into an invasive, life-threatening problem. Learn more about Invasive Breast Cancer with our video lesson (here).


What is the chance I will die of my DCIS?

The risk is very low. The most comprehensive study (here) on the subject in 2015 showed that the risk of dying from any type of breast cancer 20 years after having your DCIS treated with a lumpectomy and radiation is about 1%. One take-home message from this study is that you have plenty of time to make decisions with your breast specialists about how to best treat your DCIS.


Lumpectomy or Mastectomy for DCIS?

Removal of the area of DCIS with surgery is usually the first treatment. A lumpectomy removes the area with a surrounding margin of normal tissue. It is a great surgery if the area of DCIS is small. Radiation is generally recommended after surgery to further lessen the risk of the DCIS or an invasive cancer growing back in that area of the lumpectomy. Some women who are older or have a lower-risk type of DCIS sometimes can avoid radiation after a lumpectomy.


A mastectomy is generally recommended only if DCIS involves a large area of the breast and thus would not be a good candidate for a lumpectomy and radiation. A mastectomy for DCIS does not make you live longer, but it does reduce the chance of cancer growing back in that breast. Radiation is generally not needed after a mastectomy for DCIS. Take our video lesson on Lumpectomy or Mastectomy (here) to learn more. You and your breast surgeon must work closely together to decide what surgery is best for your unique cancer situation.


Should I take “anti-estrogen” medicines for DCIS?

When someone is diagnosed with DCIS, the pathologists will run special studies on the tumor cells to determine if Estrogen receptors and Progesterone receptors are present. If your DCIS is “Estrogen receptor positive,” taking anti-estrogen medications for 5 years can lessen the chance of developing a new breast cancer (either DCIS or invasive cancer) over the next 5 to 10 years if you had a lumpectomy. Taking “tamoxifen” or an “aromatase inhibitor” medication for this purpose is called “chemoprevention.” If a woman has bilateral mastectomies there is no need for chemoprevention because the breast tissue has been removed.


Women with DCIS are felt to have an increased risk of developing new cancers in both breasts in the future. We do not yet fully understand why DCIS is a marker for increased risk. Taking these medications can reduce the risk of new breast cancers in these higher risk women, but these drugs are not without potential side effects and risks. That is why a “risk vs benefit” discussion with a medical oncologist is important. If your DCIS is Estrogen receptor negative there may be less benefit from chemoprevention medications.


You may qualify for genetic testing if you have DCIS.

DCIS is now known to be associated with the BRCA gene mutation in a similar way as women with invasive breast cancer. The BRCA (Breast Cancer) gene is commonly referred to as “The Breast Cancer Gene.” If someone inherits a broken version (mutation) of this gene at conception, they carry a very high lifetime risk of breast cancer and ovarian cancer. Most breast cancers are not the result of the BRCA mutation. In fact, it is estimated that the BRCA and similar genetic mutations cause only 10 to 15% of all breast cancers. It is important to ask your physicians if you meet the guidelines for genetic counseling and testing. Review our video lesson on BRCA Genetic Testing (here) for more details to see if genetic testing may apply to you.


Can I avoid radiation after my lumpectomy?

Most women will benefit from radiation to reduce the risk of a “local recurrence” of their cancer in that breast. For years, we have been trying to identify which women are at lower risk of recurrence after a lumpectomy and can avoid radiation. It is important to state that the “standard of care” treatment generally includes radiation after a lumpectomy. There may be a few exceptions that may allow you to avoid radiation. If you are over 70 years old and have a favorable type of DCIS you may consider a lumpectomy only, with close mammographic follow up with your breast surgeon. Make sure to ask your breast surgeon and radiation oncologist if the risks vs. benefits favor radiation or just close observation without radiation.

What is the Oncotype DX Breast DCIS genomic test?

A “genomic assay” can occasionally be used to look further into the cells of your DCIS to estimate if you are a low risk for local recurrence of cancer in your breast over the next 5 to 10 years without radiation. There are other more important factors used to estimate your risk of recurrence after a lumpectomy for DCIS. The Oncotype DX test can play a role in this decision in some situations. If you are very motivated to avoid radiation after your lumpectomy, ask your breast surgeon and radiation oncologist about this test.


Can I avoid surgery completely for “lower risk” DCIS?

Again, a lumpectomy followed by radiation for DCIS is felt to be the best way to reduce the risk of breast cancer returning within the breast. If it does recur in the breast, the new growth can be an invasive cancer that will require more surgery and could possibly threaten your life. There are active debates and ongoing clinical trials to see if we can safely identify women with “low risk” DCIS who can be treated with surgery alone or even no surgery with close follow up. This is a complex topic, but received great media attention in 2015 after a Time Magazine cover article (here) outlined the question, “Are we overtreating DCIS and breast cancer?” A good medical overview of this dilemma by researcher Dr. Laura Esserman is located (here). It will take years to better determine how we can identify and treat lower risk DCIS less aggressively with the same good cancer outcomes. At this point in time, observation is not considered a successful treatment option.


Patient-Friendly References:

This is a detailed outline (here) of treatment options for women with DCIS written specifically for patients. The NCCN is a consortium of organizations and governmental agencies to promote quality breast cancer care.


Their information on DCIS (here) is directed towards up-to-date treatment options. It contains some of the most relevant information about breast cancer. This site is created for patients by the American Society of Breast Surgeons.


  • Oncotype DX Breast DCIS Score
    This genomic assay (here) can be used for some patients to help determine if they can safely avoid radiation after a lumpectomy for DCIS. Genomic Health, Inc. is a leading provider of genomic-based diagnostic tests.


This video for patients from Myriad Genetics is an excellent overview of genetic testing, BRCA mutations, and how they are managed.




To view the video click on the image or (here). Myriad Genetics is a global leader in genetic testing and personalized medicine.


More Detailed References:

This is a one-page diagram (here) of how treatment decisions are commonly made for non-invasive DCIS. It simplifies almost everything about treating DCIS into an easy-to-understand format. The M.D. Anderson Cancer Center is located in Houston, Texas and is one of the leading cancer centers in the world.


  • astro.org
    Information about radiation therapy is located on this site. You can search within their site using the term “DCIS” to find more specific treatment information. The American Society for Radiation Oncologists is the leading organization for clinicians who perform radiation therapy for cancer.


If you want to get deep into the details, this free 200-page pdf document (here) has guidelines to help clinicians to make treatment recommendations about nearly all aspects of breast cancer. You can easily register (here) as a non-professional to get access and more information about breast cancer. The National Comprehensive Cancer Network is the leading organization in developing clinical guidelines.



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