Six-Month Short-Interval Imaging Follow-Up for Benign Concordant Core Needle Biopsy of the Breast: Outcomes in 1444 Cases With Long-Term Follow-Up

Objective: The purpose of this study is to assess whether 6-month imaging follow-up after benign core needle breast biopsy is important for patient outcomes and whether it depends on nonspecific versus definitive benign biopsy results.

Materials and methods: Consecutive breast biopsies from 2003 to 2010 were analyzed. Benign concordant lesions with at least 2 years of follow-up were assessed. Pathologic abnormalities were further characterized as having definitive or nonspecific features. A two-tailed Fisher exact test was used to assess the difference in pathologic features among lesions that had progressed.

Results: Of 3256 cases, 1705 biopsies in 1602 women were benign concordant and were recommended for 6-month imaging follow-up; the compliance rate was 94.9%. Of these, 1444 biopsies were confirmed as benign with long-term follow-up or excision. At pathologic analysis, 805 (55.7%) benign lesions had definitive features and 639 (44.3%) had nonspecific features. Thirty-four (2.4%) lesions progressed; this was similar for the lesions with definitive (2.6%) and nonspecific (2.0%) features (p = 0.60). The false-negative rate was 0.18%, with a mean of 5.0 cores sampled per lesion.

Conclusion: For lesions with benign concordant biopsy results, selection of the follow-up interval should not be dictated by whether the pathologic features are definitive or nonspecific. The number of lesions that progress at imaging follow-up is low. The false-negative rate is low, regardless of modality or lesion type. A low false-negative rate is achievable with a reasonable number of core samples. The 6-month follow-up interval benefits only a small number of patients. Our results suggest that routine imaging after core needle biopsy is safe.