Ductal Carcinoma in Situ (DCIS)

Ductal carcinoma in situ (DCIS) is a very early form of breast cancer. With this disease, cancer cells line the milk ducts in one or both of your breasts. Milk ducts are tubes that carry milk from the lobes of your breasts to your nipples so you can breastfeed.

The term “in situ” means cancer cells haven’t spread outside your milk ducts. Healthcare providers may call DCIS noninvasive or pre-invasive breast cancer.

What are the symptoms of ductal carcinoma in situ (DCIS)?

This disease may not cause symptoms. Routine mammograms detect the disease in 9 out of 10 cases. When this disease does cause symptoms, they may include:

• A lump in your breast
• Itchy skin
• Nipple discharge

What causes ductal carcinoma in situ?

DCIS happens when healthy cells in your milk duct mutate (change). Experts aren’t sure why these changes occur.

Risk factors

Some issues may increase your risk, including:

• Age and sex: Females over age 30 have a greater risk.
• Breast health history: Dense breasts, family or personal history of breast cancer, and atypical hyperplasia can increase your risk. So can previous radiation therapy directed to your breasts or chest, especially at a young age.
• Genetics: Inheriting BRCA 1 and BRCA 2 genetic mutations, or other genes associated with breast cancer, increases your risk.
• Reproductive health: Your risk may be higher if you get your period before age 12, have a baby after age 30 or start menopause after age 55. You may also have increased risk if you’ve never been pregnant or breastfed.

Having a risk factor doesn’t mean you’ll get DCIS. If you have a risk factor, ask your healthcare provider about your risk for DCIS.

What are the complications of ductal carcinoma in situ?

Without treatment, some cases of DCIS can become invasive breast cancer. These cells can break through the duct wall into breast tissue. If tests show you have DCIS, it’s important to get treatment as soon as possible.

Some treatments for DCIS may affect your bone health or have other side effects. Ask your healthcare provider whether you need any additional screenings or follow-ups.

How doctors diagnose ductal carcinoma in situ

Your provider may do tests to confirm you have DCIS, including:

• Diagnostic mammogram: This test provides more detailed views of your breast tissue compared to a routine screening mammogram.
• Breast biopsy: Providers use this test to confirm that cancer cells are in your breast(s).

DCIS stages and grades

Healthcare providers classify cancer as stage 0 to 4. DCIS is always stage 0. They also classify the disease by the way cancer cells appear when viewed under a microscope. There are three DCIS grades:

• Low-grade: The cancer cells look a lot like healthy breast cells and grow slowly.
• Intermediate-grade: The abnormal cells look a bit like healthy breast cells. They grow more quickly than low-grade cells.
• High-grade: The cancer cells look completely different from healthy breast cells and grow uncontrollably.

How is DCIS treated?

Breast cancer surgery is the most common treatment. You may have radiation or hormone therapy after your surgery.

• Breast-conserving surgery: Your surgeon removes all cancer cells and some nearby healthy tissue. This procedure is also called a lumpectomy.
• Mastectomy: With a mastectomy, your surgeon removes your entire breast. You may have this procedure if DCIS involves a large area, is found in several separate areas or can’t be completely removed with a lumpectomy.
• Hormone therapy: For the hormone receptor positive DCIS, this medication reduces the risk of DCIS or invasive breast cancer developing in either breast.
• Radiation therapy: This treatment kills any remaining cancer cells after a lumpectomy, and it lowers the risk of cancer coming back in the same breast.

Some people have breast reconstruction surgery after a mastectomy.

What can I expect if I have this condition?

You’ll see your provider every six to 12 months for five years after treatment. You’ll have annual checkups and mammograms. But don’t hesitate to talk to your healthcare provider anytime there’s a change in your breasts.

Treatment cures almost all cases of DCIS.