By Dr. Kathleen Ruddy

women's healthDuctal carcinoma in-situ (DCIS) is a premalignant abnormality found in the ducts of the breast. Traditionally, DCIS was treated with surgery and (sometimes) radiation therapy. However, such radical therapy may not always be necessary and other, less severe forms of treatment may be perfectly appropriate.

What is the nature of DCIS?

DCIS consists of abnormal cells found within the ducts of the breast. These abnormal cells are not cancer, per se, but they can occasionally progress over time to life-threatening invasive breast cancer.

How is DCIS usually diagnosed?

DCIS typically presents as an abnormality on screening mammogram, usually in the form of new and suspicious microcalcifications. Occasionally, DCIS is discovered during a biopsy done for other reasons, such as a troublesome breast mass, cyst, or abnormal nipple discharge.


Women with DCIS who elect to have only lumpectomy without additional radiation therapy have approximately three times the recurrence rate as those who undergo radiation therapy following lumpectomy. (Women who elect mastectomy do not require radiation therapy.) Furthermore, in the instances in which DCIS does recur, there is a 50% chance that the tumor will recur as invasive, life-threatening breast cancer. This is why in most cases, women who elect lumpectomy for DCIS are usually encouraged to have radiation therapy to reduce the risk of local recurrence, and, more importantly, to reduce the chance that the recurrence will appear in the form of life-threatening, invasive disease. However, some patients may not require radiation therapy if they have a very mild form of DCIS that has a very low probability of progression to invasive disease.

Is DCIS a form of breast cancer?

No, DCIS is not a form of breast cancer, per se. However, DCIS may be discovered in the presence of an area of invasive, life-threatening breast cancer, or it may progress to invasive breast cancer over time.

Traditionally, what has been the preferred treatment for DCIS?

Women with DCIS have traditionally had three surgical options: lumpectomy to remove all breast tissue affected by DCIS, lumpectomy followed by radiation therapy, or complete mastectomy

Is it necessary to remove the opposite breast when DCIS is found in one breast?

No, it is not necessary to remove the opposite breast when DCIS is discovered in only one breast.

Are there any additional treatments given to women with DCIS?

Some women with DCIS are given an anti-estrogen drug like tamoxifen which blocks the growth of the majority of cases of DCIS. Typically, women take tamoxifen, or its equivalent, for 5-10 years following their surgery.

Do most cases of DCIS progress to invasive, life-threatening breast cancer?

There are several different types of DCIS and each has a different risk of progressing to invasive breast cancer, but, on average, less than half of all cases of DCIS will progress to invasive breast cancer if simply observed and not treated.

What other, less radical treatment options are available to women with DCIS?

Women must consult a breast cancer expert before they elect less radical treatment options such as tamoxifen only or simply observation over time. Because DCIS has such a relatively low risk of progression to invasive disease, less radical therapies increasingly seem appropriate if the patient appears to be a good candidate based on the professional opinion of a breast cancer expert.

Ductal carcinoma in-situ (DCIS) is a non-life threatening abnormality found in the ducts of the breast that occasionally may progress to life-threatening invasive breast cancer. Traditionally, surgery to remove the DCIS tissue, followed by radiation therapy, or simple mastectomy have been the treatments of choice. Many women are also given an anti-estrogen drug like tamoxifen to reduce the risk of recurrence of DCIS. But because many cases of DCIS have a a very low probability of recurring at all, or recurring as invasive breast cancer, other less radical treatments such a tamoxifen alone or simple observation and close follow up are increasingly seen as reasonable alternatives to more radical surgery; that is, provided the patient consults a breast cancer expert who agrees that non-surgical treatment is appropriate.

If you’d like to receive more information about breast cancer and find out what the Breast Health and Healing Foundation is doing to battle the disease, please sign up for our newsletter. You can sign up here:

Scientific Breakthroughs Start Here!

We believe there's a better way-- and we are going to find it! Join our mailing list to receive the latest news and updates from our team.

You have Successfully Subscribed!