Multicenter randomized trial of active monitoring versus guideline-concordant care for low-risk ductal carcinoma in situ

The multicenter randomized COMET trial compared active monitoring (follow-up every 6 months with breast imaging and physical examination) versus guideline-concordant care (surgery with or without radiation therapy) for newly diagnosed HR-positive grade 1 or grade 2 ductal carcinoma in situ (DCIS) of the breast in women aged 40 years or older. The primary end point was 2-year Kaplan-Meier cumulative risk of ipsilateral invasive cancer diagnosis. This risk was 5.9% in the guideline-concordant care group versus 4.2% in the active monitoring group, indicating tot active monitoring was not inferior to guideline-concordant care. The characteristics of the invasive tumors were not significantly different between the groups The authors conclude that these data support the short-term safety of active monitoring compared with guideline-concordant care in patients with low-risk DCIS (visual abstract).