High malignancy yield in core needle biopsy of BIRADS 3 breast lesions with calcification

10568 Background: Breast cancer screening programmes reduce mortality but result in increased numbers of breast biopsies. Stereotactic and ultrasound-guided core needle biopsy yield similar results to each other and to open biopsy. Study: Analysis of prospectively-acquired data relating to 174,338 screening mammograms performed in BreastCheck between Jan 2001 to Oct 2004. Relative use of ultrasound and stereotactic guidance for core needle biopsy is ascertained, and malignancy yields analysed. Results: In this time period, 174,338 screening mammograms discovered a total of 2782 lesions requiring further assessment. Of 2760 complete records, 1066 were BiRads R3–5 (39%) and 1033 of these (97%) had CNB. Guidance was provided exclusively by ultrasound in 737 (71%), and by stereotaxis in 270 (26%) of cases. There were no differences in malignancy yield of ultrasound versus sterotactically-guided CNB of R4 and R5 lesions (approximately 50% and 90% respectively). The malignancy yield in R3 lesions was significantly higher when performed with stereotactic guidance (12%) than when performed with ultrasound-guidance (5%) and both were significantly higher than R3 biopsy malignancy yields reported in the literature. Conclusion: Almost all BIRADS 3, 4 and 5 lesions are biopsied. The relatively high malignancy yield in R3 biopsies, particularly those with calcification, supports current practice. No significant financial relationships to disclose.