Ductal Carcinoma in Situ Treatment

Ductal carcinoma in situ (DCIS) is a noninvasive form of breast cancer that begins in the milk ducts, which carry milk from the lobules to the nipple. The abnormal cells are confined to the lining of the ducts and have not spread into the surrounding breast tissues. For this reason, DCIS is sometimes referred to as stage 0 breast cancer.

Researchers believe ductal carcinoma in situ develops when cells in the milk ducts undergo harmful DNA changes that cause them to grow uncontrollably. Although the precise triggers of these genetic mutations are unclear, several factors may increase the risk. These include advanced age, dense breast tissue, early-onset menstruation, late-onset menopause, prior radiation exposure to the chest, a personal or family history of breast cancer and certain inherited gene mutations, such as BRCA1 and BRCA2.

Most people with ductal carcinoma in situ do not experience noticeable symptoms. In many cases, the condition is detected through routine screening mammography, which may reveal clusters of microcalcifications. Usually harmless, these tiny, white calcium deposits can result from normal aging, cell turnover or a benign breast condition. However, certain tight, irregularly shaped clusters may indicate DCIS. Less commonly, the condition may cause a breast lump, nipple discharge or changes in breast appearance.

Ductal carcinoma in situ is one of the most common breast conditions in the United States. According to the American Cancer Society, tens of thousands of new cases are diagnosed each year. DCIS primarily affects women, particularly those older than 50, but it can also occur in younger women and, rarely, in men.

Even though ductal carcinoma in situ is noninvasive, it can increase the risk of developing invasive breast cancer if left untreated. Therefore, timely treatment is essential. The goals are to remove or destroy the abnormal cells, prevent progression to invasive breast cancer and reduce the risk of recurrence.

Surgery for ductal carcinoma in situ

Surgery is the primary and foundational treatment for nearly all cases of DCIS. Usually, this approach is recommended to remove the abnormal cells and confirm that they have not spread beyond the breast ducts.

Surgical treatment options for ductal carcinoma in situ may include:

• Lumpectomy, also known as breast-conserving surgery, to remove the DCIS and a margin of surrounding healthy tissue
• Mastectomy to remove the entire breast, which may be recommended if DCIS is widespread, present in multiple areas or cannot be completely removed with a lumpectomy
• Sentinel lymph node biopsy, which may be performed in certain cases, particularly if a mastectomy is planned or there is concern about invasive cancer

Surgery for DCIS can be highly effective, but it carries potential risks and side effects. These include pain, swelling, infection, bleeding, changes in breast shape or appearance and, in rare cases, lymphedema if lymph nodes are removed. When planning the procedure, the healthcare team will discuss strategies to manage these risks and support recovery.

Radiation therapy for ductal carcinoma in situ

Radiation therapy uses high-energy beams to target and destroy abnormal cells in a localized area of the body. While this approach is often used after lumpectomy to reduce the risk of recurrence in the treated breast, it may be unnecessary after mastectomy for DCIS, especially if the entire breast was removed and the margins are clear.

Radiation delivery techniques for DCIS treatment may include:

• Accelerated partial breast irradiation (APBI) targeting only the area around the lumpectomy site
• External beam radiation therapy (EBRT) directed at the whole breast
• Hypofractionated radiation therapy, which delivers higher doses over a shorter period

Side effects of radiation therapy may include skin irritation similar to a sunburn, fatigue, breast swelling and changes in skin texture. Most side effects are temporary, although some patients may experience long-term changes in breast firmness or appearance.

Hormone (endocrine) therapy for ductal carcinoma in situ

If DCIS is hormone receptor-positive (HR+), which means the cancer cells grow in response to estrogen or progesterone, endocrine therapy may be considered after surgery. The goals are to prevent the development of invasive breast cancer in either breast and reduce the risk of DCIS recurrence.

Hormone therapy medications that may be used for treating ductal carcinoma in situ include:

• Anastrozole
• Exemestane
• Letrozole
• Tamoxifen

Typically, endocrine therapy is taken for five years. Side effects may include hot flashes, joint pain, fatigue and, in rare cases, blood clots or bone thinning, depending on the medication used.

My goal is to help patients get the right treatment for their cancer. If we can safely spare some women from unnecessary surgery and radiation, we should.

Bethany Niell, MD, PhD

Clinical trials for ductal carcinoma in situ

Clinical trials are important investigative studies designed to evaluate emerging approaches to cancer prevention, diagnosis and treatment. They may explore the effectiveness of novel medications, advanced radiation delivery techniques, new surgical strategies or ways to tailor therapy based on individual risk.

If a patient is interested in participating in a clinical trial, the healthcare team can identify an appropriate study based on the patient’s diagnosis, tumor characteristics and personal preferences. Participation may provide the patient with access to promising new therapies before those options become widely available. Throughout the study, the patient will also be closely monitored by a specialized research team while contributing to the advancement of knowledge and the improvement of future treatment standards.

Chemotherapy for ductal carcinoma in situ

Chemotherapy is a systemic treatment that uses powerful drugs to destroy rapidly dividing cells throughout the body. Because DCIS is noninvasive and confined to the breast ducts, chemotherapy is not typically part of standard treatment. However, if invasive cancer is found in addition to DCIS, chemo may be recommended based on the tumor characteristics and overall risk. In these rare cases, the medications used may include:

• Cyclophosphamide
• Docetaxel
• Doxorubicin
• Paclitaxel

Because chemotherapy can affect healthy, fast-growing cells in addition to cancer cells, it may cause side effects, such as fatigue, nausea, hair loss, increased risk of infection, anemia and changes in appetite. Most side effects are temporary and can be managed with supportive care.

Targeted therapy for ductal carcinoma in situ

Targeted therapy focuses on the specific molecules involved in cancer cell growth. For pure DCIS, this treatment approach is not routinely used. However, if invasive HER2-positive breast cancer is identified alongside DCIS, targeted therapy may be considered.

Targeted therapy drugs that may be used for invasive breast cancer include:

• Trastuzumab
• Pertuzumab

The side effects of targeted therapy can vary depending on the drug used, but may include infusion-related reactions, diarrhea and, in some cases, cardiovascular effects that require monitoring.

Immunotherapy for ductal carcinoma in situ

Immunotherapy is designed to boost the natural ability of the body’s immune system to recognize and attack cancer cells. At this time, immunotherapy is not a standard treatment for DCIS, primarily because the cancer is noninvasive and can typically be managed with localized therapies, such as surgery and radiation therapy. For specific subtypes of invasive breast cancer that occur with DCIS, however, immunotherapy using pembrolizumab, a PD-1 inhibitor, may be considered. Potential side effects include fatigue, skin reactions, diarrhea and inflammation of organs, such as the thyroid, lungs or liver, due to immune system activation.

Benefit from world-class care at Moffitt Cancer Center

At Moffitt, patients with DCIS can receive comprehensive, individualized care, including advanced diagnostic imaging, state-of-the-art treatment technologies and access to innovative clinical trials, all within a National Cancer Institute-designated Comprehensive Cancer Center. Our multispecialty team of surgical oncologists, medical oncologists, radiation oncologists, radiologists and pathologists collaborates to develop an individualized treatment plan for each patient, focusing on the best possible outcome and quality of life.

If you would like to learn more about ductal carcinoma in situ treatment, you can request an appointment with a specialist in the renowned Don & Erika Wallace Comprehensive Breast Program at Moffitt by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.

References

Treatment of Ductal Carcinoma in Situ (DCIS)
Ductal Carcinoma In Situ (DCIS) Treatment | Susan G. Komen®