If you have a diagnosis of DCIS, you may hear and read about many risks associated with it. 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 (and DCIS diagnosed more often), 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 other ways to treat DCIS, especially low-risk DCIS.
One study looked at the records of large numbers of women who were diagnosed with low-risk DCIS and compared women who underwent surgery and/or radiation with those who did not. The survival rate over a 10-year period was very close for both groups - about 98%.
This study does not mean that low-risk DCIS should not be treated, but it does suggest that surgery and radiation might not have been needed in every case. Researchers are now trying to see if there might be other ways to manage low-risk DCIS.
One approach is active monitoring. Active monitoring involves regular mammograms and check-ups with a provider. If no changes in the breast are seen, active monitoring continues. If any changes are seen or felt, tests, such as a biopsy, may be done to investigate the changes. The test results may confirm that active monitoring can be continued, or they may indicate that surgery and radiation therapy are needed.
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.
With surgery, the DCIS area and tissue around it are removed and the risk of future invasive cancer is reduced. Depending on the type of operation you have, some or all of your breast will be removed. The tissue that is removed in the operation is carefully examined. At this stage, invasive cancer is found in around 6 in every 100 patients. More surgery (re-excision) or radiation therapy may be required to remove or destroy remaining cells. You will have the reassurance that everything has been done to reduce your risk of invasive cancer. You may experience side-effects from the surgery and/or radiation. Some side-effects may affect your daily life and some can be long-term. Surgery (and radiation if needed) may cause pain and change the look and feel of your breast. This may affect you physically and emotionally. Some patients choose to have additional surgery to reconstruct the breast; this can have other side-effects.
With active monitoring, you have a check-up and mammogram every six months to look for any changes in the breast. While you stay on active monitoring, you will avoid the side-effects of surgery and radiation. Approximately 8 or 9 out of every 10 patients should be able to stay on active monitoring for at least 10 years. Approximately 6 in every 100 patients will have invasive cancer that may worsen, said another way, 94 out of 100 will not. You may experience anxiety from wondering whether your DCIS is growing or changing. If any changes are seen in your breast that concern your doctor, you will be advised to have further tests, such as a biopsy. You might be able to stay on active monitoring. However, if the changes are suggestive of invasive cancer, you will be advised to have surgery (and radiation if needed). It is possible that you might need more extensive treatment at this stage than if you had undergone it at the time your DCIS was first diagnosed.
It is important to note that with both active monitoring and surgery there are risks of invasive cancer developing in the breast with DCIS, the other breast, or somewhere else in your body.
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 understand the trade-offs and make decisions. If uncertain about treatment options, women may find it helpful to seek a second medical opinion. This is appropriate 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.