External Validation of a Pragmatic Scoring System for Predicting Upgrade of Atypical Ductal Hyperplasia at the Time of Surgery.

BACKGROUND

Atypical ductal hyperplasia (ADH) carries a variable risk of upgrade at the time of surgery to ductal carcinoma in situ (DCIS) or invasive malignancy. We sought to externally validate a pragmatic upgrade risk scoring system previously demonstrated to have an upgrade rate of 0-2% in patients with a risk score of 0 out of 5.

METHODS

A multicenter, retrospective review of all percutaneous biopsies containing ADH was performed from 2017 to 2023. Women aged ≥ 18 years who underwent diagnostic mammography and surgical excision for pathologic correlation were included.

RESULTS

Among the 183 cases included, the mean age was 58 years ± standard deviation 11, and 91 patients (50%) reported a family history of breast cancer. Most biopsies were stereotactic (75%), vacuum-assisted (84%), and used 9-gauge needles (73%). Three of 14 (21%) patients with a risk score of 0 were upgraded to DCIS following surgical excision. Seven (19%) patients had a risk score of 1 upgraded - six to DCIS and one to an estrogen receptor-positive/progesterone receptor-positive/human epidermal growth factor receptor 2-negative invasive ductal carcinoma measuring 5.45 mm in largest diameter. On multivariate analysis, age, mammographic lesion size, and suspicion of DCIS on biopsy were predictive of upgrade.

CONCLUSIONS

The risk model evaluated generally predicts the risk of upgrade of ADH at excisional biopsy but may underestimate the upgrade rate in the lowest-risk cohort. Because of the small sample size, further work is needed to determine whether the rate of upgrade is truly low enough in this lowest-risk cohort to recommend against excisional biopsy.