What is Ductal Carcinoma in Situ

Ductal carcinoma in situ (DCIS) is a noninvasive type of breast cancer that occurs when abnormal cells develop in the lining of a breast duct, a thin tube that carries milk from the breast’s glandular tissue to the nipple. At the early stage, the abnormal cells remain confined to the walls of the duct. If left untreated, ductal carcinoma in situ can spread to nearby tissues and progress into invasive breast cancer.

In the United States, ductal carcinoma in situ is relatively common, accounting for approximately 1 in 5 new breast cancer diagnoses. It primarily affects women, particularly those 50 and older, though it can also occur in younger women and, rarely, in men.

"My treatment team knew my background and they weren't letting that just go to the side."

Read Rebecca's story

Schedule your screening mammogram

What causes ductal carcinoma in situ?

DCIS develops when cells in a breast duct lining undergo harmful changes that cause the cells to grow abnormally and uncontrollably. The precise causes of the cellular mutations that lead to the development of breast cancer are not yet fully understood.

What are the risk factors for ductal carcinoma in situ?

Known risk factors for DCIS include:

• Advanced age – Among women, the average age at diagnosis is 54.
• Family history – Breast cancer in a close relative, such as a mother, sister or daughter, increases the risk of DCIS in women and, to a lesser extent, men.
• Personal history – Women previously diagnosed with breast cancer or a benign breast condition are at heightened risk for DCIS.
• Hormone replacement therapy (HRT) – Long-term use of HRT, especially after menopause, can increase the risk of breast cancer.
• Early-onset menstruation or late-onset menopause – Women who begin menstruating before age 12 or enter menopause after age 55 have prolonged exposure to the female hormone estrogen, which is associated with increased cancer risk.
• Inherited cancer predisposition syndromes – Certain gene mutations, particularly in breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2), can increase the risk of DCIS.
• Obesity – Fatty tissue (adipose) produces excess estrogen, high levels of which are associated with an increased risk of several types of cancer, including DCIS.

What are the symptoms of ductal carcinoma in situ?

Usually, DCIS does not cause noticeable symptoms. Instead, the condition is often detected when a routine mammogram shows small groupings of white spots or flecks (calcifications) in the breast tissue.

Though rare, possible symptoms of ductal carcinoma in situ can include:

• Breast lump – A hard, firm, solid mass with irregular edges that can be felt in the breast
• Nipple discharge – Clear, bloody or otherwise unusual nipple discharge (other than breast milk)
• Breast discomfort – Pain or tenderness in the breast

How is ductal carcinoma in situ diagnosed?

DCIS is primarily diagnosed through a mammogram, which can reveal abnormal calcifications in the breast tissue. If a physician identifies a suspicious area, they will typically order a biopsy, which involves removing a small sample of cells for microscopic examination by a pathologist.

Several types of biopsies can be used to diagnose ductal carcinoma in situ, including:

• Fine needle aspiration (FNA) – FNA involves the use of a thin needle to extract cells or fluid from the suspicious area.
• Core needle biopsy – The most commonly used biopsy technique for DCIS, a core needle biopsy involves the use of a hollow needle to remove small tissue samples from the affected area of the breast.
• Stereotactic biopsy – A specialized type of core needle biopsy, stereotactic biopsy involves the use of mammography to help the physician precisely locate and sample abnormal areas of the breast.
• Excisional biopsy – Also known as a wide local excision, this surgical procedure involves removing the entire suspicious area along with a slim margin of surrounding tissue.

In some cases, additional imaging tests, such as magnetic resonance imaging (MRI) or ultrasound scans, may be used to help the physician assess the extent of the DCIS and guide treatment decisions.

How is ductal carcinoma in situ treated?

DCIS treatment can vary depending on the extent of the tumor and the patient’s preferences. Options may include:

• Observation – In a low-risk case, the physician may suggest a “wait and watch” approach.
• Lumpectomy – A surgeon will remove the tumor and a slim margin of surrounding healthy tissue, which can preserve most of the breast.
• Mastectomy – A surgeon will remove the breast tissue, nipple, areola and skin.
• Radiation therapy – Often used after a lumpectomy, radiation therapy can target any remaining microscopic cancer cells and help reduce the risk of recurrence
• Hormone therapy – If the cancer is hormone receptor-positive, medications such as tamoxifen or aromatase inhibitors may be used to block the effects of estrogen and help reduce the risk of recurrence.

Benefit from world-class care at Moffitt Cancer Center

The multispecialty team in Moffitt’s nationally renowned Don & Erika Wallace Comprehensive Breast Program takes a collaborative, patient-first approach to breast cancer care. In addition to cutting-edge diagnostic and treatment services complemented by compassionate supportive services, our patients have access to promising new therapies available only through our robust clinical trials program.

If you would like to learn more about ductal carcinoma in situ, you can request an appointment with a breast cancer specialist at Moffitt by calling 1-888-663-3488  or submitting a new patient registration form online. We do not require referrals.