# To VAE or not to VAE: outcomes of radial scars/complex sclerosing lesions and papillary lesions without atypia in the King's College Hospital breast service (2017–2023)

## TL;DR

The study finds that radial scars and papillary breast lesions without atypia have low cancer upgrade rates, suggesting some may avoid surgery and be monitored instead.

## Contribution

The study provides new data on the malignancy risk of radial scars and papillary lesions without atypia in a clinical setting.

## Key findings

- Radial scars/complex sclerosing lesions without atypia had a 1% upgrade to cancer after excision.
- Papillary lesions without atypia had a 4% upgrade to cancer after excision.
- Radiological size was not significantly associated with cancer upgrade in either lesion type.

## Abstract

Since there is currently limited data regarding the risk of malignancy that radial scars/complex sclerosing lesions (RS/CSL) or papillary lesions without atypia carry, we reviewed all such cases treated at King's College Hospital between January 2017 and June 2023 to determine the upgrade rates following immediate excision and longer follow‐up.

Patients were identified using electronic database searches. An ‘upgrade’ was defined as the presence of ductal carcinoma in situ (DCIS) or invasive breast carcinoma (IBC) on excision at the biopsy site. One hundred and two patients had RS/CSL (85% screen‐detected; 15% symptomatic). Only one (1%) of the 90 patients who underwent excision was upgraded to DCIS; none to IBC. On longer follow‐up, four patients (4%) developed ipsilateral DCIS/IBC, while one patient developed contralateral DCIS with microinvasion. Two hundred and twenty‐six patients had papillary lesions without atypia (42% screen‐detected; 58% symptomatic). Eight (4%) of the 179 patients who underwent excision were upgraded to DCIS; none to IBC. On longer follow‐up, one patient developed ipsilateral DCIS; another patient developed contralateral IBC. For both lesions, radiological size was not significantly associated with atypia/upgrade (P > 0.05; Mann–Whitney U‐test).

Since RS/CSL without atypia carry a low upgrade risk (1%), these patients could avoid excision and be followed up with mammographic surveillance. However, further data are needed for this change in practice to be considered. Papillary lesions without atypia appear to be more heterogeneous in behaviour, carrying an upgrade risk of 4%. Current treatment guidelines should not change until we better understand the biology of these lesions.

Radial scars/complex sclerosing lesions (RS/CSL) without atypia have a low upgrade rate (1%) and could possibly be monitored radiologically, thus avoiding excision. Papillary lesions without atypia have a higher upgrade rate (4%) and should continue to undergo vacuum excision until we better understand these heterogeneous lesions.