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DCIS FAQs for Patients, Family & Friends

Many people have never heard of DCIS, and it can be difficult for someone newly diagnosed to explain what it is. Below are answers to frequently asked questions that patients, friends and family may have.

Is DCIS “different than Breast Cancer”?

Yes. DCIS stands for Ductal Carcinoma in Situ, and it is sometimes called “stage zero breast cancer.” DCIS is, however, quite different to invasive breast cancer. DCIS represents abnormal cells completely confined within the milk ducts. As long as these cells stay within the ducts, they remain DCIS, and may never cause any harm to a woman’s health. Invasive breast cancer, on the other hand, includes stages 1-4, breaks out of the ducts and invades other parts of the breast. It may eventually spread to other parts of the body.

Why does DCIS have the word “carcinoma” in its name?

The abnormal cells in DCIS look like cancer cells, but they are not able to break free of the milk duct. For this reason, it may never cause health problems in a woman’s lifetime. The word “carcinoma” can be confusing when it is used for DCIS. In fact, studies show the term can contribute to women rushing into treatment decisions. It is important to remember that a DCIS diagnosis is not an emergency and it is important to take time to learn about different treatment options to make decisions that feel right.

How likely is DCIS to become invasive cancer?

In addition to DCIS being different from invasive cancer, there are different types or “grades” of DCIS that come with different levels of risk. Results of recent studies have shown that 7 or 8 out of 10 women (70-80%) with DCIS fall into a “low-risk” category. This type of DCIS may never become invasive cancer or cause any health problems in a woman’s lifetime. About 1 in 10 women with DCIS will experience invasive breast cancer, usually many years after their DCIS diagnosis. Researchers actually do not know if a future invasive breast cancer comes from the original DCIS, or if it is a brand new cancer. To answer this question, studies are currently being done to understand how DCIS is related to invasive breast cancer.

How does a woman know if she has “low-risk” DCIS?

“Low-risk” includes low to intermediate grade DCIS. The grade, size and other characteristics of DCIS will be written on a pathology report. A second pathologist’s opinion can provide reassurance of an accurate diagnosis and is recommended before making a treatment decision.

Is DCIS life-threatening?

No. All DCIS is non-invasive. In other words, as long as abnormal cells remain in the ducts, they are not life threatening. It is important for women to take time to evaluate benefits versus harms of all treatment options, and to feel confident and supported in their decisions for treatment or close monitoring.

How is DCIS discovered and diagnosed?

Most women have no signs, symptoms, lumps or tumors. Tiny white specs called “micro-calcifications” are seen by a radiologist (a specialist who studies x-rays) on mammograms. A needle biopsy is usually recommended to remove a piece of breast tissue that is then examined under a microscope by a pathologist (a physician who specializes in studying tissue). Mammograms and other imaging methods cannot diagnose DCIS. A needle or surgical biopsy is currently the only way a woman can be diagnosed with DCIS.

How is DCIS treated?

For many years, DCIS was considered to be a single condition. All grades of DCIS were treated the same as invasive breast cancer. Standard treatment for both invasive breast cancer and DCIS involves surgery with or without radiation, and sometimes endocrine (hormone-blocking) therapy. Newer research studies, however, have concluded that “low-risk” DCIS has a very small chance of ever being associated with invasive breast cancer. “Active Surveillance” – close monitoring of low-risk DCIS – is now being studied to learn if women who do not have immediate surgery have the same excellent outcomes as those who choose standard treatments. If outcomes of both surgery and active surveillance are similar, women may be offered Active Surveillance as a DCIS treatment option in the future and many women will be spared potential physical and emotional side effects and the financial burdens of treatments. A similar approach is currently being used for prostate cancer, thyroid cancer, and some melanoma cancers.

What is Active Surveillance?

Active Surveillance is sometimes called “close monitoring.” It is currently being studied as another way to manage DCIS. Active surveillance is utilized in other low-risk cancers such as prostate cancer. With regards to DCIS, Active Surveillance includes exams and imaging tests on a regular schedule to closely observe if any changes appear. If a significant change is seen on imaging, a biopsy will be recommended. More standard treatment may also be started at that time. The Comparison of Operative to Monitoring and Endocrine Therapy for Low-risk DCIS (COMET) Study is a clinical trial that is currently testing Active Surveillance as an option for low-risk DCIS.

How much time is there to decide on treatment for DCIS?

DCIS is not an emergency. There is no need for women to feel rushed or pressured. It is important to understand your pathology report. The type, grade and size of DCIS will be noted. Ask your doctor about tests which can give you more understanding of your individual risk of a future invasive breast cancer such as the Oncotype DCIS score. Evaluate the benefits and harms of each treatment. You may also want to get a second pathologist’s opinion. This can help provide reassurance that the diagnosis is correct.

Why are there so many differing opinions about DCIS and its treatment?

In recent years, new information about DCIS has led researchers, physicians and patients to question the aggressive “standard of care” treatment protocol. Many physicians have stated that a randomized clinical trial is necessary before a less aggressive treatment approach such as Active Surveillance can be offered to women as a treatment option. Over-treatment of DCIS has become a hot topic. Through a clinical trial such as the COMET Study, advances in knowledge may lessen the uncertainty and confusion associated with whether DCIS requires aggressive treatment or not.

What if my doctor says surgery is required?

Immediate surgery is the current standard of care for all types and grades of DCIS. Several clinical trials comparing Active Surveillance to immediate surgery for DCIS are underway. If you have low-risk DCIS and a doctor recommends surgery, you may want to get more opinions and inquire about clinical trials before making a final decision.

How can I find more information about DCIS and clinical trials? is a new website developed by medical professionals and DCIS patient advocates. It provides current information about DCIS, clinical trials, and patient-centered educational resources.

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