Utility of 6-month follow-up imaging after a concordant benign breast biopsy result.

Purpose: To determine the utility of 6-month follow-up imaging after benign concordant image-guided percutaneous breast biopsy results.
Materials and Methods: The institutional review board approved this retrospective, HIPAA-compliant study; informed consent was waived. Findings from consecutive stereotactic and ultrasonographically guided core breast biopsies performed from 2001 to 2005 were analyzed and included lesions with benign pathologic findings without atypia found to be concordant with imaging at a consensus conference. Rebiopsy recommendation rates and positive predictive values (PPVs) for detecting malignancy at each follow-up interval were measured and compared by using a two-tailed Fisher exact test.
Results: In 2244 biopsies, lesions in 1465 were benign, concordant, and not excised. In 1057 of 1465 (72.2%) biopsies with imaging follow-up (average, 26.4 months; range, 4.0-49.9 months), recommended rebiopsy rates were 0.8% (four of 526), 0.5% (three of 588), and 1.0% (eight of 802) at 6-month, 12-month, and long-term follow-up intervals, respectively. When the initial follow-up did not occur until 12 months, the recommended rebiopsy rate was 0.9% (three of 322), compared with 0.8% (four of 526) at 6 months (P > .99), and no malignancies were found in either group. One malignancy was detected at the long-term follow-up interval (PPV for excision recommended, 12% [one of eight]; PPV for excision performed, 20% [one of five]).
Conclusion: Because rebiopsy recommendation rates and PPVs did not differ in the 6- and 12-month groups, a 6-month follow-up imaging examination, in the context of a formal concordancy consensus conference, may not contribute to improved breast cancer diagnosis.
Supplemental Material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10091824/-/DC1.
(© RSNA, 2010)