Impact of bilateral breast cancer on prognosis: synchronous versus metachronous tumors.

Background: The clinical significance of bilateral breast cancer is unclear and its influence on prognosis is controversial.

Materials And Methods: Between 2005 and 2009 we identified 110 cases of bilateral breast cancer (BBC) ; 49 patients had synchronous (duration between the occurrence of carcinoma in both breasts was less than 12 months) and 61 had metachronous (duration was more than one year with no ipsilateral local recurrence). We compared the patient characteristics including age, menopausal status, clinical stage, tumor size, histological classification, lymph node status, and hormone receptor and Her-2 status. We also compared the treatment given and overall and disease free survival (DFS) of both groups.

Results: Synchronous cases tend to present more aggressively than metachronous cases and age at first presentation adversely affects survival. The 5 year overall survival was 78.7% for metachronous and 60% for synchronous. Patients with positive hormonal status had better five year disease free survival in metachronous compared to synchronous cases, at 76% and 63%, respectively. Age at first presentation >45years had better DFS (65%) compared to those with age ≤45 years (52%) at 5 years follow up.

Conclusions: Patients with synchronous breast cancer may have worse prognosis. Young age and hormone receptor negative were risk factors in our study. Close follow up and early detection of contralateral breast cancer is mandatory.