What is low-risk DCIS?

A level of risk is often also added to describe DCIS, which can be categorized as “low” or “high” risk to indicate the probability (likelihood) that it will develop into invasive breast cancer. Women with low-risk DCIS are less likely to have invasive breast cancer in the future than women with high-risk DCIS. While low-risk DCIS has features that indicate the woman has a low probability of developing invasive breast cancer, this is not the same as no risk. These risk levels are also a source of debate.

Until now, very little research has directly compared the experiences and outcomes of patients receiving different treatments for low-risk DCIS. Research that has been done has involved patients with all types of DCIS, including those with low-risk and high-risk DCIS. Research that combined patients with low- and high-risk DCIS has suggested that fewer women will develop invasive breast cancer or die of breast cancer if they have surgery compared with those who do not have surgery. However, active monitoring was not studied (or was not an option) in this research. The lack of clarity about the research findings, and particularly how relevant they are to patients with low-risk DCIS, is why more research is needed.