title: Properties of Synchronous Versus Metachronous Bilateral Breast Carcinoma with Long Time Follow Up.
abstract: BACKGROUND
  Breast cancer is the most common cancer type among women with increasing incidence rates, improved prognosis and survival. According to the localization of the tumor, breast cancer is designated as unilateral (UBC) or bilateral (BBC). BBC can be classified as synchronous (SBBC) or metachronous (MBBC) based on the time interval between the diagnosis of the first and the secondary tumors. According to the guideline of WHO 2012, BBC is generally defined as SBBC when contralateral breast carcinoma is diagnosed within 3 months. The aim of this study was to compare the characteristics and patterns of metastasis of BBC patients with UBC.
  
  
  METHODS
  A cohort of 768 patients with breast cancer treated at the Turkish Ministry of Health-Izmir Bozyaka Research and Training Hospital between 1976 and 2012 were studied. Survival analysis was performed comparing UBC and BBC patients. In addition, evaluations were performed in patients with SBBC and MBBC sub-groups. We used a 3-months interval to distinguish metachronous from synchronous.
  
  
  RESULTS
  When clinical and histopathological parameters were statistically evaluated, ER status, event-free and overall survival were found to be significant between UBC and BBC patients. In comparison of SBBC and MBBC patients, age, histological type of tumor, event-free and overall survival were found to be significant.
  
  
  CONCLUSIONS
  BBC cases were found to show worse prognosis than UBC cases. Among BBC, SBBC had the worst prognosis based on overall survival rates.
authors.affiliation: Pathology, Faculty of Medicine, Adnan Menderes University, Aydin, Turkey, E-mail : drnuket2003@yahoo.com.
authors.forename: Nuket
authors.initials: N
authors.lastname: Eliyatkin
authors.forename: Baha
authors.initials: B
authors.lastname: Zengel
authors.forename: Ayse
authors.initials: A
authors.lastname: Yagci
authors.forename: Erdem
authors.initials: E
authors.lastname: Comut
authors.forename: Hakan
authors.initials: H
authors.lastname: Postaci
authors.forename: Adam
authors.initials: A
authors.lastname: Uslu
authors.forename: Safiye
authors.initials: S
authors.lastname: Aktas
mesh_terms: D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology*; D002277:Carcinoma / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000401:mortality / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D016019:Survival Analysis; D015996:Survival Rate