PB.35: Comparison of large-bore vacuum-assisted biopsy and surgical diagnostic excision biopsy in B3 breast lesions

Introduction

B3 lesion management is unclear. Despite varying malignancy risk, diagnostic excision was conventional, revealing malignancy in some and benign features in others. Large-bore vacuum-assisted biopsy (VAB, 7 to 8G) can enhance pathological certainty, providing reassurance of benignity, or identify co-existing malignancy, with many groups moving towards VAB to replace surgical excision biopsy. However, little research has addressed the accuracy of VAB compared with surgical biopsy in this situation.

Methods

From November 2011 to May 2013, we incorporated VAB into the management of all B3 lesions identified by 10/14G biopsy. Excision biopsy was still performed on any lesion initially identified as B3 with atypia, unless upgraded by VAB. The VAB result and surgical excision outcomes were compared.

Results

A total of 181 lesions were identified and considered for VAB. Atypia was present in 102 lesions. Sixty-five of 102 lesions had VAB, with 11 upgraded to malignancy. Of the 54/65 lesions not upgraded by VAB, 25 proceeded to excision biopsy, revealing DCIS in seven. A total 37/102 lesions did not have VAB (fibro-epithelial lesions/technical factors); malignancy was identified in five at excision biopsy. The overall malignancy rate was 23/102 (22.5%). Of VAB/excision biopsy discordant lesions, average tissue obtained at VAB was 2.4 g, compared with 2.9 g in concordant lesions (NS).

Conclusion

VAB can increase preoperative detection of malignancy, but has an associated miss rate. Thirty per cent of the DCIS present in B3 lesions with atypia was missed by second-line VAB. This is important to appreciate as women are placed on surveillance programmes for B3 lesions following VAB, but without completion excision biopsy.