CLINICAL QUESTION

In women with low-risk ductal carcinoma in situ (DCIS), is active monitoring for evidence of invasive progression noninferior to guideline-concordant usual care, including surgery with or without radiation?

BOTTOM LINE

At 2 years of follow-up, the study found that active monitoring in women with low-risk DCIS was not inferior to current guideline-based usual care (surgery with or without radiation). Results were similar in women who initiated endocrine therapy. The investigators will report further results to assess the continued safety and patient acceptability of active monitoring. (Level of Evidence = 1b−)

SYNOPSIS

DCIS is conventionally treated with surgery, with or without radiation or endocrine therapy, similar to low- to intermediate-risk invasive cancer. The investigators identified women with newly diagnosed, screen-detected low-risk DCIS (hormone receptor–positive grade 1 or 2 without evidence of invasive cancer). Eligible patients (n = 957; median age 64 years) were randomly assigned to guideline-concordant usual care or active monitoring. Guideline-concordant usual care included surgery with or without radiation treatment depending on choice of surgery. Diagnostic mammography was performed every 12 months for the affected and unaffected breast. Active monitoring consisted of diagnostic mammography every 6 months for the affected breast and every 12 months for the unaffected breast. Patients with physical examination or imaging findings concerning for disease progression underwent core needle biopsy and surgery for identified invasive cancer.