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 asunilateral (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 guidelineof WHO 2012, BBC is generally defined as SBBC when contralateral breast carcinoma is diagnosed within 3months. The aim of this study was to compare the characteristics and patterns of metastasis of BBC patientswith UBC. Materials and
Methods: A cohort of 768 patients with breast cancer treated at the Turkish Ministryof Health-Izmir Bozyaka Research and Training Hospital between 1976 and 2012 were studied. Survival analysiswas performed comparing UBC and BBC patients. In addition, evaluations were performed in patients withSBBC 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 andoverall survival were found to be significant between UBC and BBC patients. In comparison of SBBC and MBBCpatients, 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 prognosisbased on overall survival rates.