Real World Performance of Screening Breast Ultrasound Following Enactment of Connecticut Bill 458

The purpose of this article was to retrospectively evaluate the benefits of screening breast ultrasound in women with dense breast tissue following enactment of Connecticut Bill 458 in October 2009. This bill mandated that women be informed of their breast density and the possible benefit of ultrasound as an additional screening modality. Institutional approval was obtained from the institutional review board for this retrospective study. A total of 5519 women with dense breasts were screened with ultrasound in the year after the law went into effect from October 2009 to September 2010 (post law group). We focused on the women who had negative mammograms and biopsy recommendations based on ultrasound findings (BIRADS 4 and 5). The data were compared with those from a group of 1319 women who were screened with breast ultrasound before the law went into effect between October 2008 and September 2009 (pre law group). Prior to the law, ultrasound studies were performed only at the referring clinician's request. Of the 5,519 women in the post law group, 10 malignant lesions were found, with a cancer detection rate of 0.18%, biopsy rate of 3.3%, and a positive predictive value of 5.5%. The tumor size on ultrasound ranged from 4 to 15 mm; mean 9.7 mm. Sentinel lymph node biopsy was negative in 7 of 10 patients. Of the 1,319 women in the pre law group, 20 biopsies were recommended, all of which were benign. No malignancies were detected in the pre law group. Establishment of a formal screening breast ultrasound program as an adjunct to mammography in women with dense breasts increased our cancer detection rate following enactment of Connecticut Bill 458.