Diagnostic accuracy of a stereotaxically guided vacuum-assisted large-core breast biopsy program in Canada.

OBJECTIVE: To assess the accuracy rate associated with 11-gauge vacuum assisted large-core breast biopsy (VALCBB) at our institution. METHODS: 673 consecutive VALCBBs performed between September 1997 and March 2000 were evaluated. For most of the benign VALCBB specimens, accuracy was determined by the stability of the lesions on follow-up mammography. When possible, histological results of specimens obtained from VALCBB and of specimens obtained from surgical excision were compared. Modified accuracy rates were calculated. RESULTS: Of the 673 biopsies, 499 (74%) were benign; for the 315 benign lesions for which complete follow-up information was available, a greater than 99% modified accuracy rate was obtained. The modified accuracy rate for the 174 nonbenign lesions was 95%. Thus, VALCBB yielded an overall modified accuracy for both benign and nonbenign lesions of 97.9%. CONCLUSION: VALCBB provides accurate histological results for biopsy of suspicious lesions of the breast.