What is DCIS?

Ductal carcinoma in situ (DCIS) is the growth of abnormal cells in the milk ducts of the breast. It's a very early form of non-invasive breast cancer. Non-invasive means that the cells haven't spread. Some cases of DCIS will become invasive breast cancer, but it's impossible to know which ones.

What causes it?

The exact cause of DCIS isn't known. Getting older and being female may play a part.

What are the symptoms?

Most of the time, DCIS doesn't cause symptoms. But in some cases, symptoms can include a lump in the breast or fluid or blood coming from the nipple.

How is it diagnosed?

DCIS is usually found during a mammogram, where it may look like a pattern of white areas or bits of calcium (calcifications). To diagnose DCIS, your doctor will remove a sample of breast tissue and look at it under a microscope. This is called a breast biopsy.

How is it treated?

Two kinds of surgery are used to treat DCIS. They are:

Breast-conserving surgery.

It removes just the affected area.

Mastectomy.

It removes the whole breast.

If you had breast-conserving surgery, your doctor may suggest radiation therapy. You may also take medicines that block hormones. These medicines make it harder for some kinds of breast cancer cells to grow.

No matter which treatment you choose, your chance of surviving is very high.

In some rare cases, you may be able to delay treatment. If you and your doctor choose to wait, your doctor will watch you closely to see if DCIS cells change into a type that can spread. This is called active surveillance.

Your doctor will discuss your risk and treatment options. This includes your feelings about keeping your breast and your worry about the cancer coming back.