Stereotactic large-gauge core biopsy: its role in the diagnosis of non-palpable mammographic abnormalities presenting to a screening service.

A retrospective study of large-gauge core biopsy (LGCB) of 206 non-palpable mammographic abnormalities detected at routine screening in a community-based clinic accredited with the Australian National Program for the Early Detection of Breast cancer, was performed to ascertain the role of LGCB as an alternative to diagnostic surgical biopsy within such a programme. Of the 51 malignancies diagnosed by LGCB and proceeding to treatment, no false-positives were found and agreement as to the presence, or otherwise, of invasion between core and open biopsy was 95%. Once malignancy was established by LGCB, one-stage treatment was possible in 74.5% of cases. A total of 114 lesions were considered to be benign and returned to routine screening. One interval cancer subsequently developed in this group. Incongruity between the pathological diagnosis from core biopsy and the mammographic image occurred in 29 cases, representing potential mistargeting in 14.1% of cases. Four cancers were discovered in this group when the patients subsequently proceeded to surgical biopsy, making an overall false-negative rate of 2.4%. No core biopsy sample was considered inadequate for pathological assessment and no lesion proved inaccessible to targeting. There was no long-term morbidity. We believe that LGCB is a safe, reliable and cheaper alternative to diagnostic surgical biopsy, but a close correlation of pathology and mammography is required to avoid the erroneous return of women to routine recall.