Clinical Outcomes of Mammographic BI-RADS 3 Lesions in the Community Hospital Setting

Per the Breast Imaging Reporting and Data System (BI-RADS) manual, a lesion designated as BI-RADS 3 should have less than a 2% chance of becoming malignancy. With this study, we evaluated the outcome of patients given a BI-RADS 3 designation in the community hospital. Specifically, whether our cancer detection rate for BI-RADS 3 lesions was less than 2% and comparable to rates obtained at other institutions.

The records of 1037 patients given a BI-RADS 3 on screening mammogram were reviewed over a 1-year period between May 2007 and May 2008. A total of 142 of these patients were lost to follow-up, leaving 885 patients. Some of these patients had more than 1 BI-RADS 3 lesion during this study period, yielding a total of 923 BI-RADS 3 lesions to evaluate out of the 885 patients remaining. Of these, 478 of the patients' lesions were biopsied. The pathology was then reviewed to determine whether the lesions were cancerous.

Only 6 of the 882 lesions initially classified as a BI-RADS 3 were later diagnosed as cancer, or 0.65% of the study population. The positive predictive value of receiving a BI-RADS 3 was 99.3%, which demonstrates a high accuracy in predicting that a lesion is not cancerous.

Most lesions that are diagnosed as a BI-RADS 3 have a very low probability of eventually being diagnosed as cancer. The findings from this study are comparable to studies performed at other institutions.