Objective: This study was designed to assess the diagnostic indexes of sonographic surveillance with mammography for the detection of metachronous contralateral breast cancer.
Materials and methods: Between January 2003 and December 2003, 1,706 breast sonographic examinations were performed by three radiologists in 1,256 Asian women with a history of surgery for breast cancer in one breast as an adjunct screening test to mammography in an academic medical center. We evaluated the biopsy recommendation rate, a diagnostic index, of the combination of whole-breast sonography and mammography for the detection of contralateral metachronous breast cancers and the positive predictive value (PPV) of this biopsy recommendation rate.
Results: Based on 1,706 examinations in 1,256 women, the biopsy recommendation rate was 3.5% per patient and 2.6% per examination. The PPV of the biopsy recommendation rate was 41.0% with 18 breast cancers diagnosed (cancer detection rate, 1.4% per patient and 1.1% per examination). Among these cancers, two were detected on sonography alone. One false-negative cancer was found on the next sonographic examination but could not be seen on the next mammographic examination.
Conclusion: With a false-negative rate of only 0.06% and a PPV of 41.0% for the biopsy recommendation rate, our results suggest that annual sonography could be a useful adjunctive tool to mammography for the detection of metachronous contralateral cancers.