Excisional biopsy of borderline lesions after large bore vacuum-assisted core needle biopsy- is it necessary?

The current recommendation for borderline breast lesions after core needle biopsy is for surgical excision due to a high rate of pathologic underestimation. With the use of vacuum-assisted core needle (VACN) biopsy devices, upgrade rates have improved, but still average 20 per cent. We routinely use larger bore VACNs (7- and 8-gauge) than previously reported (9 to 11-gauge). The aim of this study is to evaluate the upgrade rate to malignancy in patients undergoing VACN using larger bore needles. VACN biopsies were performed in 902 patients. Of those, 87 were recommended excisional biopsy for borderline or noncorrelating lesions and 66 underwent the procedure. Two patients were upgraded to cancer, for an overall upstage rate of 3 per cent. Both of these underestimations were in patients that initially had atypical ductal hyperplasia. In the patients not excised, no patient developed further cancer. A 7- or 8-gauge needle was used in 57 per cent of patients, greater than 90 per cent removal of the initial lesion was accomplished in 53 per cent of cases, and there were no bleeding complications. This study suggests that upgrade rates decline with larger bore biopsy needles with near complete excision of the initial lesion, and that some borderline lesions may potentially be managed nonoperatively.