37P - To excise or not to excise: Preventive management of early breast cancer in atypical ductal hyperplasia patients

Background

Atypical Ductal Hyperplasia (ADH) is a pre-malignant high-risk breast lesion, with morphological features similar to that of ductal carcinoma in situ (DCIS). The WHO diagnosis of ADH is defined as cytonuclear and architectural atypia <2mm in size. The current standard management is surgical excision, due to its reported 10-30% risk of upgrade to breast cancer. However, an increasingly observed alternative management utilizes a conservative approach with annual radiological follow up, quoting lower upgrade risks of 3-5%. Indications for conservative follow-up include low-risk patients or intial biopsy with vacuum assistance. Our primary aim is to investigate the ADH upgrade risk in a Singapore cohort, with a secondary goal of comparing upgrade cancer rates in upfront surgical management versus upgrade rates on conservative surveillance, to discuss feasibility of adopting a primarily conservative approach for the population.

Methods

A retrospective study was performed of 221 patients diagnosed with ADH between January 2013 to June 2023 in a tertiary institute. Initial biopsy histology, management approach and patient outcomes were evaluated. Outcome was measured by upgrade to early breast cancer. Odds ratio & relative risk was used to adjust for demographics, risk profile and biopsy methods.

Results

221 patients were diagnosed with ADH on biopsy, of whom 8 opted for surveillance. There was an overall upgrade risk of 31.22%, with 75.36% of upgrade histology being DCIS. Of all upgrades, 97.10% were diagnosed on upfront surgical excision after a mean period of 39 days, while 2.9% were diagnosed after a period of conservative surveillance. Of the 8 patients opting for conservative management, 1 patient received repeat biopsy and another 2 patients received surgical excision after a mean period of 268 days.

Conclusions

Our findings of a 31% upgrade risk of ADH to early breast cancer, consistent with that of reported literature, still support the case for upfront surgical excision of ADH. We recommend upfront surgical excision of ADH once discovered on initial biopsy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.