Analysis of residual cancer after diagnostic breast biopsy: An argument for fine-needle aspiration cytology

Background: Diagnostic breast biopsy (DxBx) requires an effective strategy for strategy for successful treatment of breast cancer by lumpectomy or mastectomy. Clearance of margins is required to achieve local control. Methods: We reviewed 844 malignant diagnostic biopsies. The strategy was to perform DxBx on all nonpalpable lesions and fine-needle aspiration (FNA) on all palpable lesions. When FNA was equivocal, DxBx was performed. After positive DxBx, either the biopsy cavity or FNA-positive breast mass was excised, and margins were documented with touch preparation cytology analysis (TPC) and frozen section (FS) as necessary to achieve negative margins. Results: Ourside institutions referred 430 excisional biopsies. Two hundred twenty-five (52.3%) were found to have residual cancer at surgical excision. Our institution performed 414 biopsies: 169 were performed on nonpalpable lesions in which 58% had residual tumor at resection; 245 were diagnosed by FNA of palpable lesions. Residual disease was found in 12 (5%). Conclusions: Of patients who undergo DxBx, >50% have residual breast cancer. It is recommended that (a) FNA be performed on all palpable masses or DxBx of nonpalpable masses; when cancer is diagnosed, proceed to surgical excision. (b) When lumpectomy is the option, margins should be reexcised and intraoperatively evaluated with TPC and FS at the time of axillary dissection.