title: Preoperative Breast Magnetic Resonance Imaging and Contralateral Breast Cancer Occurrence Among Older Women With Breast Cancer.
abstract: OBJECTIVE
  Preoperative magnetic resonance imaging (MRI) detects occult contralateral breast cancers (CBCs) in women with breast cancer, but the impact of detection on long-term CBC events is unclear. We examined whether MRI use decreases the occurrence of CBCs and the detection of stages II to IV disease among women who develop a CBC.
  
  
  METHODS
  Analyzing the SEER-Medicare database, we assessed overall, synchronous (< 6 months after primary cancer diagnosis), and subsequent (ie, metachronous) stage-specific CBC occurrences in women who were diagnosed with stages I and II breast cancer during 2004-2009 and who were observed through 2011.
  
  
  RESULTS
  Among 38,971 women with breast cancer, 6,377 (16.4%) received preoperative MRI. After propensity score matching, and compared with women who did not undergo MRI, preoperative MRI use was significantly associated with a higher synchronous CBC detection rate (126.4 v 42.9 per 1,000 person-years, respectively; hazard ratio, 2.85; P < .001) but a lower subsequent CBC detection rate (3.3 v 4.5 per 1,000 person-years, respectively; hazard ratio, 0.68; P = .002). However, the 5-year cumulative incidence of CBC remained significantly higher among women undergoing MRI compared with those not undergoing MRI (7.2% v 4.0%, respectively; P < .001). The analyses of projected CBC events for 10,000 patients who receive MRI indicated that, after a 5-year follow-up, MRI use would detect an additional 192 in situ CBCs (95% CI, 125 to 279) and 120 stage I CBCs (95% CI, 62 to 193) but would not have a significant impact on stages II to IV CBC occurrences (∼ 6; 95% CI, -21 to 47).
  
  
  CONCLUSIONS
  An increased synchronous CBC detection rate, attributable to MRI, was not offset by a decrease of subsequent CBC occurrence among older women with early-stage breast cancer, suggesting that preoperative MRI in women with breast cancer may lead to overdiagnosis.
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT. shiyi.wang@yale.edu.
authors.forename: Shi-Yi
authors.initials: SY
authors.lastname: Wang
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT.
authors.forename: Jessica B
authors.initials: JB
authors.lastname: Long
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT.
authors.forename: Brigid K
authors.initials: BK
authors.lastname: Killelea
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT.
authors.forename: Suzanne B
authors.initials: SB
authors.lastname: Evans
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT.
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Roberts
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT.
authors.forename: Andrea
authors.initials: A
authors.lastname: Silber
authors.affiliation: Shi-Yi Wang, Yale University School of Public Health; and Shi-Yi Wang, Jessica B. Long, Brigid K. Killelea, Suzanne B. Evans, Kenneth B. Roberts, Andrea Silber, and Cary P. Gross, Yale Cancer Center and Yale University School of Medicine, New Haven, CT.
authors.forename: Cary P
authors.initials: CP
authors.lastname: Gross
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D018426:SEER Program; D014481:United States / Q000453:epidemiology