DCIS (Ductal Carcinoma In Situ)
DCIS is breast cancer at the earliest stage: stage 0. DCIS forms and is contained to your milk ducts (tubes that carry milk to the nipple) only. It hasn’t spread beyond the milk ducts into other parts of your breast (in situ means in its original place).
DCIS isn’t life-threatening, but if you’re diagnosed with DCIS, you have a higher risk of developing invasive breast cancer later in life.
About 20% to 25% of new breast cancers diagnosed in the United States are DCIS. 1
DCIS symptoms
DCIS generally has no symptoms. In some cases, DCIS may cause a lump or nipple discharge. But in most cases, DCIS is found by mammogram, where it looks like small clusters of white spots.
DCIS diagnosis
Diagnosing DCIS involves a combination of procedures and almost always includes:
A noticeable lump is rare with DCIS, though in some cases your doctor may be able to feel a small lump in your breast.
Nearly all cases of DCIS are diagnosed by mammogram or other imaging. Calcium deposits in the breast (called breast calcifications), which may be a sign of DCIS, appear white on a mammogram. Other imaging tests that may be used are:
ultrasound
breast MRI
If there is a suspicious area on your mammogram or other imaging tests, a doctor will perform a procedure called a biopsy to remove some breast cells or tissue from this area. A pathologist will then analyze these cells or tissue under a microscope.
DCIS grade
Because all DCIS is stage 0, your doctor will also use the grade of the DCIS to decide on the best treatment options for you. The grade describes how much the cells look like healthy breast cells. There are three grades of DCIS:
These cells look only a little bit different from healthy breast cells and grow slowly. Low-grade DCIS is less likely to come back (recur) after being removed by surgery than moderate- or high-grade DCIS.
These cells grow faster and are more likely to come back after surgery than low-grade DCIS and less like healthy cells than low-grade DCIS. Moderate-grade DCIS is also called intermediate-grade.
These cells look very different from healthy breast cells and grow faster than low- and moderate-grade DCIS. High-grade DCIS is the most likely to come back after surgery. High-grade DCIS may be described as comedo or comedo necrosis, which means there are areas of dead cancer cells inside the DCIS.
Your doctor will likely do other tests to collect more information on the characteristics of the DCIS. These tests, as well as the results of your biopsy, make up the parts of your pathology report.
Information that may be part of your DCIS pathology report includes:
size of the DCIS
hormone receptor status
tumor margins
DCIS treatment
Every DCIS is different. You and your doctor decide on the best treatment plan for your unique situation, taking into account:
the size of the DCIS
the grade of the DCIS
your health history
your risk of breast cancer, including any family history
your personal preferences
Standard treatments for DCIS are:
lumpectomy alone, if the DCIS is very small and low-grade; lumpectomy removes the DCIS, plus a small rim of healthy tissue around it (called the margin), preserving as much of the breast as possible
lumpectomy followed by radiation therapy; radiation after lumpectomy helps to ensure that no cancer cells are left after surgery
mastectomy, which removes all the breast tissue
hormonal therapy, also called anti-estrogen therapy, endocrine therapy, or hormone therapy, if the DCIS is hormone-receptor-positive
There are also genomic tests that analyze a sample of the DCIS to see how active certain genes are. The activity of these genes affects how the DCIS behaves. Either the DCISion RT test or the Oncotype DX Breast DCIS Score Test can help you and your doctor figure out how likely the DCIS is to come back and how likely you are to be diagnosed with invasive breast cancer in the future. Knowing this can help inform your decision about whether radiation would offer benefits after lumpectomy to remove the DCIS.
Follow-up care after DCIS treatment
Because of treatments they’ve received, many people who’ve been diagnosed with DCIS have a higher risk of developing other diseases as they age, including high blood pressure, heart disease, and osteoporosis. To make sure you’re regularly screened for these and other diseases, it is important to seek follow-up care.
DCIS recurrence risk
The risk of DCIS coming back (recurring) depends on a number of factors, including:
DCIS grade
DCIS size
treatments you receive
Your doctor can give you more information about your personal risk of DCIS recurrence.
Still, it’s important to remember that being diagnosed with DCIS increases your risk of developing invasive breast cancer. So you should continue to have regular mammograms or other screening tests as recommended by your doctor.
Tomlinson-Hansen, S. et al. Breast Ductal Carcinoma In Situ. Feb. 27, 2023. Available at: https://www.ncbi.nlm.nih.gov/books/NBK567766/
— Last updated on July 18, 2024 at 10:57 PM
