DCIS (Ductal Carcinoma In Situ)
Updated on October 9, 2025
DCIS is breast cancer at the earliest stage: stage 0. DCIS forms in the milk ducts (the tubes that can carry milk from the lobules to the nipple) and hasn’t spread 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 slightly 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.
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 often involves a combination of procedures.
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 mammography or other imaging. Calcium deposits in the breast (called breast calcifications), which may be a sign of DCIS, appear as white flecks on a mammogram.
If you have dense breasts or there is an area of concern that your doctor wants more information about, you may also have an ultrasound or breast MRI.
If there is an abnormal finding 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 make treatment recommendations 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 look less like healthy cells than low-grade DCIS. They also grow faster and are more likely to come back after surgery 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 usually does other tests to collect more information on the characteristics of the DCIS. The results of your biopsy and any other tests are in your pathology report.
Your pathology report may also include information on:
the size of the DCIS
the hormone receptor status of the DCIS
the size of the surgical margins, if you have lumpectomy
DCIS treatment
Every DCIS is different. You and your doctor create 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 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 and reduces the risk of recurrence (the DCIS coming back)
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 (nearly all are)
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 you and your doctor decide if radiation after lumpectomy would offer benefits.
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
Some research suggests that a number of people overestimate the risk of DCIS coming back (recurrence). It’s reassuring to know that studies show DCIS recurrence risk after lumpectomy (with or without radiation) or after mastectomy is low.
If you have a recurrence, it may be a recurrence of DCIS or invasive breast cancer. If the recurrence is DCIS, it is still non-invasive and not life threatening and can be treated with more surgery and radiation therapy, if you haven't previously received radiation. If the recurrence is invasive breast cancer, your doctor may recommend more surgery and other treatments.
Your personal risk of DCIS recurrence 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 recurrence.
DCIS prognosis
Because DCIS isn’t invasive, the National Cancer Institute doesn’t collect information on outcomes the way it does with invasive cancers. Still, the prognosis — the expected outcome of treatment — for DCIS is excellent. Nearly all people with DCIS are alive 20 years after being diagnosed.
Tomlinson-Hansen, S. et al. Breast Ductal Carcinoma In Situ. Feb. 27, 2023. Available at: https://www.ncbi.nlm.nih.gov/books/NBK567766/
