More than 62 000 women are diagnosed with ductal carcinoma in situ (DCIS) in the United States annually. Without treatment, approximately 20% to 30% of DCIS will progress to invasive cancer. However, 97% of women are treated according to guideline-concordant care (GCC) (surgery and/or radiation). An alternative for low-risk DCIS is active surveillance (AS), where mammography and physical examinations are used to monitor potential breast changes. Evidence from registries and collection of patient-reported outcomes is critical to understanding the benefits and harms of GCC vs AS for DCIS.
