title: Characteristics and Survival of Breast Cancer Patients with Multiple Synchronous or Metachronous Primary Cancers.
abstract: OBJECTIVE
  Newly developed extra-mammary multiple primary cancers (MPCs) are an issue of concern when considering the management of breast cancer survivors. This study aimed to investigate the prevalence of MPCs and to evaluate the implications of MPCs on the survival of breast cancer patients.
  
  
  METHODS
  A total of 8204 patients who underwent surgery at Severance Hospital between 1990 and 2012 were retrospectively selected. Clinicopathologic features and survival over follow-up periods of ≤5 and >5 years were investigated using univariate and multivariate analyses.
  
  
  RESULTS
  During a mean follow-up of 67.3 months, 962 MPCs in 858 patients (10.5%) were detected. Synchronous and metachronous MPCs were identified in 23.8% and 79.0% of patients, respectively. Thyroid cancer was the most prevalent, and the second most common was gynecologic cancer. At ≤5 years, patients with MPCs were older and demonstrated significantly worse survival despite a higher proportion of patients with lower-stage MPCs. Nevertheless, an increased risk of death in patients with MPCs did not reach statistical significance at >5 years. The causes of death in many of the patients with MPCs were not related to breast cancer. Stage-matched analysis revealed that the implications of MPCs on survival were more evident in the early stages of breast disease.
  
  
  CONCLUSIONS
  Breast cancer patients with MPCs showed worse survival, especially when early-stage disease was identified. Therefore, it is necessary to follow screening programs in breast cancer survivors and to establish guidelines for improving prognosis and quality of life.
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Janghee
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea. psh1025@yuhs.ac.
authors.forename: Seho
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sanghwa
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jeeye
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jegyu
authors.initials: J
authors.lastname: Ryu
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyung Seok
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seung Il
authors.initials: SI
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Byeong-Woo
authors.initials: BW
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis / Q000401:mortality*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis / Q000401:mortality*; D016609:Neoplasms, Second Primary / Q000175:diagnosis / Q000401:mortality*; D011379:Prognosis; D011788:Quality of Life; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D016019:Survival Analysis
keywords: Breast cancer; metachronous; multiple primary neoplasms; survival; synchronous