Sonographic surveillance for the detection of contralateral metachronous breast cancer in an Asian population

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.