What is ductal carcinoma in situ (DCIS)?
Ductal carcinoma in situ (DCIS) is a type of breast cancer. This is also called non-invasive or pre-invasive breast cancer. The cancer cells are found along the sides of the milk duct within the breast. Milk ducts are within each breast and are the tubes that let milk travel from the lobes (made up of lobules) to the nipple openings for breastfeeding.
DCIS is non-invasive, which means that the cancer cells are found only within the milk duct(s) and have not spread through the walls of the ducts and to other nearby tissues in the breast. It is a Stage 0 breast cancer and is treatable. Doctors characterize cancer in stages, using Roman numerals from 0, or zero, to IV, or four. In order to determine the stage of a tumor, doctors must look at the original tumor and determine where it is located, its size, and if it has been noticed in other areas. The lower the stage number, the better chance for successful treatment of the disease and for the best results.
Although DCIS is always considered Stage 0, the tumor can be any size and may be found within several milk ducts inside the breast. With proper treatment, the prognosis is excellent.
How common is ductal carcinoma in situ (DCIS)?
The American Cancer Society expects that 63,960 new cases of DCIS will be found in 2018. Today more and more women are aware of the importance of early detection and are getting mammograms each year. Because of this, the number of cases of DCIS has increased. In addition, mammography technology has greatly improved as well and is better able to detect problems at an earlier stage. An estimated 12.4% of women in the U.S. will develop invasive breast cancer at some time in their lives.
Who is affected by ductal carcinoma in situ (DCIS)?
Most women who get DCIS do not have a family history of breast cancer. Only about 5-10% of breast cancer cases are related to a genetic mutation or family history. Red flags for this include having a family history of breast cancer, especially if the cancer was discovered at a younger age, or before 50 years old. Other red flags for breast cancer that may be related to a genetic mutation include a family history of ovarian cancer, male breast cancer, multiple other cancers in the family and Ashkenazi Jewish ancestry. The most common risk factors for breast cancer include being female and getting older, and these are risk factors that cannot be changed.
Because the tissue in men’s breasts do not fully develop the way that the tissue in women’s breasts do, men do not usually get breast cancer of this type.
Symptoms and Causes
What are the symptoms of ductal carcinoma in situ (DCIS)?
DCIS generally has no signs or symptoms. A small number of people may have a lump in the breast or some discharge coming out of the nipple. According to the National Cancer Institute, about 80% of DCIS cases are found by mammography.
Diagnosis and Tests
How is ductal carcinoma in situ (DCIS) diagnosed?
The sooner this type of cancer is found, the sooner it can be treated. The following tests or procedures are usually used to diagnose DCIS:
- Breast examination: A routine breast exam is usually part of a regular physical. It is the first step in detecting breast cancer. Although DCIS does not usually come with a noticeable lump, the doctor may be able to feel an abnormal growth in the breast, such as a small, hardened spot, during a physical examination. The doctor will also look for any skin changes, nipple changes or nipple discharge. Most times, though, the abnormal growth will show up on a mammogram.
- Mammogram: DCIS is usually found during a mammogram. As old cells die off and pile up within the milk duct, they leave tiny, hardened calcium spots which show up as a shadow or white spot on a mammogram.
- Biopsy: If a spot or a shadow is found on the mammogram, the doctor will recommend a biopsy.
- Core needle biopsy: With this procedure, the doctor inserts a large needle into the breast to get a big sample of the breast tissue that looked abnormal on the mammogram. The doctor will first numb the skin at the site of the biopsy and then make a small incision in the skin to help get the needle into the breast. Because the skin has been cut, there will be a tiny scar which will fade over time.
If a needle biopsy does not get enough breast cells or tissue to properly examine, or the results are not clear cut, the doctor may suggest another biopsy.
The following procedures are considered surgery:
- Incisional biopsy: Through an incision, or a cut in the skin, the doctor can remove a sample of breast tissue to examine it further.
- Excisional biopsy: This procedure cuts out the entire lump of tissue from the breast.
Biopsies are only used to diagnose that there is cancer within the breast. If cancer is found, surgery will be recommended to remove the abnormal cells.
Management and Treatment
What types of treatment are available for ductal carcinoma in situ (DCIS)?
If a biopsy has confirmed that there are cancer cells within the breast, treatment for DCIS includes:
Lumpectomy with radiation after surgery: This is the most common treatment for DCIS. A lumpectomy is surgery that removes all of the DCIS along with a bit of the surrounding healthy breast tissue that borders the cancer growth. This is to make sure that all of the abnormal cancer cells have been removed. With a lumpectomy, the surgeon will leave the majority of the breast intact. The amount of tissue removed depends on the size and location of the DCIS.
Radiation therapy, a common cancer treatment, is a process that typically follows a lumpectomy. It is usually combined with surgery to make sure that all abnormal cells are gone. This treatment also reduces the risk of the cancer coming back.
Mastectomy: This surgery removes the entire breast and is recommended if the DCIS is found in a large area or seen throughout the breast. No radiation therapy follows a mastectomy.
Chemotherapy, or medicine that is used to kill cancer cells throughout the body, is usually not needed to treat DCIS.
Each individual case is different. The patient and doctor will decide what treatment is best for the situation.
What medication(s) treat ductal carcinoma in situ (DCIS)?
Tamoxifen may be prescribed for woman of all ages who have been treated for DCIS. In those women past menopause, the doctor may prescribe an aromatase inhibitor. These medications help lower the risk of DCIS or another type of cancer developing in either breast. If either is prescribed, it is suggested that these drugs be taken for five years after surgery.
Outlook / Prognosis
What is the prognosis for patients who have ductal carcinoma in situ (DCIS)?
Because DCIS is contained within a specific area of the breast and has not spread, the disease can be controlled and cured with appropriate treatment. After treatment, the outcome for the patient with DCIS is usually excellent.
However, those patients who have had DCIS, even if treated successfully, are at a greater risk than people who have never had breast cancer to have the cancer return or for another type of breast cancer to develop.
What type of follow-up care can be expected after treatment of ductal carcinoma in situ (DCIS)?
Each patient is different, and the doctor will work with each individual on a follow-up plan after surgery and radiation therapy. Typically, a patient can expect to see the doctor for a physical exam every six to 12 months for five years after treatment, then annually after that. An annual mammogram will also be recommended.
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