title: Ultrasound screening of contralateral breast after surgery for breast cancer.
abstract: OBJECTIVE
  To determine whether supplemental screening ultrasound (US) to mammography could improve cancer detection rate of the contralateral breast in patients with a personal history of breast cancer and dense breasts.
  
  
  METHODS
  During a one-year study period, 1314 screening patients with a personal history of breast cancer and dense breasts simultaneously underwent mammography and breast US. BI-RADS categories were given for mammography or US-detected lesions in the contralateral breast. The reference standard was histology and/or 1-year imaging follow-up, and the cancer rate according to BI-RADS categories and cancer detection rate and positive biopsy rate according to detection modality were analyzed.
  
  
  RESULTS
  Of 1314 patients, 84 patients (6.4%) were categorized as category 3 with one interval cancer and one cancer which was upgraded to category 4A after 6-month follow-up US (2.5% cancer rate, 95% CIs 1.5-9.1%). Fifteen patients (1.1%) had category 4A or 4B lesions in the contralateral breast. Four lesions were detected on mammography (two lesions were also visible on US) and 11 lesions were detected on US and 5 cancers were confirmed (33.3%, 95% CIs 15.0-58.5%). Six patients (0.5%) had category 4C lesions, 2 detected on mammography and 4 on US and 4 cancers were confirmed (66.7%, 95% CIs 29.6-90.8%). No lesions were categorized as category 5 in the contralateral breast. Cancer detection rate by mammography was 3.3 per 1000 patients and that by US was 5.0 per 1000 patients, therefore overall cancer detection rate by mammography plus US was 8.3 per 1000 patients. Positive biopsy rate of mammography-detected lesions was 66.7% (4 of 6) and that of US-detected lesions was 40.0% (6 of 15).
  
  
  CONCLUSIONS
  US can be helpful to detect mammographically occult breast cancer in the contralateral breast with high positive biopsy rate and low category 3 rate in patients with a previous history of breast cancer and dense breasts.
authors.affiliation: Department of Radiology, Seoul Metropolitan Government Seoul National University, Boramae Medical Center, Republic of Korea.
authors.forename: Seung Ja
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea.
authors.forename: Se-Yeong
authors.initials: SY
authors.lastname: Chung
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Chang
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea.
authors.forename: Nariya
authors.initials: N
authors.lastname: Cho
authors.affiliation: Department of Surgery, Seoul National University Hospital, Republic of Korea.
authors.forename: Wonshik
authors.initials: W
authors.lastname: Han
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea. Electronic address: moonwk@snu.ac.kr.
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
mesh_terms: D000328:Adult; D001706:Biopsy; D001940:Breast / Q000473:pathology* / Q000601:surgery; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods
keywords: BI-RADS category; Breast cancer; Contralateral breast; Mammography; Ultrasonography; Ultrasound breast screening