If you have a diagnosis of DCIS, you may hear and read about many risks associated with it. Risks are patterns that researchers observe when they study a large number of patients. They use these patterns (called probabilities) to determine how likely something is to happen. If you have not yet visited the section on “understanding risk” you may wish to do so before reviewing this section.
Risks can be used to help you make decisions that you feel are best for you. Below are some of the ways we know about the potential risks of DCIS and how to understand them.
As mammography became more widely used, more and more DCIS was diagnosed. Doctors believed that it was important to treat all DCIS, both low- and high-risk, with the same type of treatments (such as surgery and radiation used for more advanced cancers). Over time, studies have suggested that there might be better ways to treat DCIS, especially low-risk DCIS.
One study looked at the records of large numbers of women who were diagnosed with DCIS and compared women who underwent treatment with those who did not. The survival rate over a 10-year period was very close for both groups — about 98%. This is shown in the graph below (Sagara et al.)
This study does not mean that DCIS should not be treated, but it does suggest that it may be subject to overtreatment. Researchers are now trying to see if there might be other ways to manage low-risk DCIS. One possibility is called active surveillance. Active surveillance is a program of monitoring. It involves closely watching the DCIS and only recommending more aggressive treatment (such as surgery or radiation) if the DCIS changes. A number of studies are looking at this question, including the Comparison of Operative to Monitoring and Endocrine Therapy (COMET) study in the United States (see the active surveillance menu item under treatments).
There are trade-offs among management strategies for DCIS, especially low-risk DCIS. A trade-off means giving up one thing in return for another. For example, lumpectomy reduces the risk of invasive breast cancer. Yet the trade-offs from surgery may include both short and long-term side effects. These possible side effects include disfigurement, pain and loss of feeling. There can be surgical complications and a possibility of more surgery. This may be needed to ensure all the DCIS is removed.
Active surveillance involves no immediate treatment so you will not have to deal with the treatments and their side effects, but there is a greater risk of changes to your DCIS over time. You will need to be very carefully watched and for some, this uncertainty may be troubling and cause anxiety. The potential risks of each treatment may be one of the things you use to understand trade-offs and make medical decisions.
Risk is one piece of information women may use to make their decisions, but there are many other factors involved, such as feelings about quality of life, work and family responsibilities, and financial considerations. Each woman may weigh these factors differently. Women should feel comfortable and supported in taking the time they need to make decisions. If uncertain about treatment options, women may find it helpful to seek a second medical opinion. This is not only appropriate but recommended for DCIS treatment because the condition is not yet fully understood. You will hear much about risk, but your personal values and preferences also play an important role in your treatment choices.