Women with atypical ductal hyperplasia (ADH), unlike those with ductal carcinoma in situ (DCIS), are denied eligibility for active surveillance clinical trials.
We applied the inclusion criteria of the Comparison of Operative to Monitoring and Endocrine Therapy (COMET) trial to the cases of women (n = 165) at the Roswell Park Cancer Institute who had a diagnosis of ADH, ADH bordering on DCIS, or low- to intermediate-grade DCIS on core biopsy taken during screening mammography. Upgrade of lesions to high risk was based on invasive carcinoma, high-grade DCIS, or DCIS with comedo necrosis.
In total, nine (5.5%) lesions were upgraded: two (1.7%) reported ADH, one (5.9%) reported ADH bordering on DCIS, and six (19.4%) reported DCIS (P = .002); and two (1.6%) reclassified ADH vs seven (17.1%) reclassified DCIS (P < .001). In multivariate analysis, only increased number of foci had the potential to predict high risk (odds ratio: 1.39; P = .06).
We conclude that ADH and ADH bordering on DCIS have lower upgrade rates than DCIS. We recommend opening an active surveillance clinical trial for women with these diagnoses.