Ductal carcinoma in situ
What is Ductal Carcinoma in Situ?
Have you been diagnosed with Ductal carcinoma in situ (DCIS)?
A diagnosis of DCIS can be confusing.
If you have DCIS, you have abnormal cells in your milk ducts which have not spread into your breast tissue. You may need treatment, but you do not have invasive breast cancer.
Is it life threatening?
In itself, DCIS isn’t life threatening; however, having DCIS can increase your risk of developing invasive breast cancer later in life.
Is it common?
Yes. In Australia, approximately 1,600 women are diagnosed with DCIS each year.
How is DCIS diagnosed?
DCIS doesn’t usually appear as a breast lump or breast change. As a result, most women with DCIS do not show any signs or symptoms of having breast cancer.
Mammograms and ultrasounds are the most common ways in which DCIS is diagnosed. If DCIS is suspected, a biopsy is usually required to confirm whether DCIS is present.
Pathologists usually attribute a grade to DCIS. The grade indicates the patterns of cancer cell growth and how fast the cells are growing. Based on what the DCIS cancer cells look like under a microscope, DCIS can be graded as high, intermediate or low.
If left untreated, high grade DCIS is likely to develop into invasive breast cancer. Low or intermediate grades of DCIS may remain as they are for many years. In some cases, however, low or intermediate grades of DCIS can develop into invasive breast cancer.
While the size and grade of DCIS can help doctors predict whether the cancer is likely to become invasive, there are no certain answers. Unfortunately it is not currently possible to know for certain if a woman will go on to develop invasive breast cancer.
I have DCIS – Will I develop invasive breast cancer in the future?
Not every woman with DCIS will develop invasive breast cancer. Your risk of developing invasive breast cancer is, however, increased if you have been diagnosed with DCIS.
Recent results from an Australian study found that between 1995 and 2005, 13,749 women were diagnosed with DCIS and that, by the end of 2005, 706 of those women had developed invasive breast cancer even though they had received treatment for DCIS.2
According to the study, women who are diagnosed with DCIS are, on average, 3.9 times more likely to develop invasive breast cancer than Australian women of a similar age who have not had DCIS.
Treatment for DCIS
Most women who are diagnosed with DCIS will be recommended treatment. This is because it is not possible to predict which women may go on to develop invasive breast cancer.
The goal of DCIS treatment is to ensure the abnormal cells in the milk ducts do not spread to the breast tissue and become invasive breast cancer, and to prevent it from returning at a later time.
Breast conserving surgery is a common treatment for DCIS. This is also called a lumpectomy, partial mastectomy or wide local incision. This surgery is sometimes followed by radiotherapy. Mastectomy may be recommended if the DCIS is widespread within the milk ducts.
Removal of lymph nodes is generally not recommended as a treatment for DCIS. If DCIS is extensive and you require a mastectomy, or if your surgeon is unsure about the presence of invasive breast cancer, you may be offered a sentinel node biopsy.
Chemotherapy is generally not used to treat DCIS after surgery. If your DCIS is oestrogen receptor positive (which means that the cancer needs oestrogen to grow), oestrogen blocking treatments may be recommended. These include tamoxifen or aromatase inhibitors such as letrozole, anastrozole or exemestane.