BRCA1/2 mutations as prognostic factors in bilateral breast cancer (BC) patients

Abstract

9647 Background: Incidence of primary bilateral BC is rare and not extending 5%. BRCA1/2 mutation carriers diagnosed with BC have a strong life time risk of developing a contralateral BC (53% vs 2%). Methods: We analyzed the group of 108 patients with bilateral BC who attended our Cancer Center between 2000 and 2002 and who gave their consent for genetic test. Patients with synchronous BC were defined as having contralateral BC within 1 year. Similarities and differences between BRCA1/2 carriers and non carriers were analyzed in terms of family history, pathology of tumor, age of diagnosis and development of contralateral BC and second cancer. Results: The median age of the group at the time of diagnosis of BC was 47 years (28–76). Before age of 50, BC developed 73% of patients, including 22% before age of 40. Synchronous BC was diagnosed in 30 (28%) patients, metachronous in 78 (72%). Family history of BC was present in 32/108 patients, and of ovarian cancer in 5/108 patients. BRCA1/2 mutation was detected in 32/108 patients. Family history of BC was identified in 46,9% of these patients, comparing to 22,4% of non carriers (p<0.05). Synchronous BC was diagnosed significantly rarer 4/32 (12.5%) in BRCA1/2 carriers than in non carriers group 26/76 (34.2%). Also patients with BRCA mutations when diagnosed were younger than non carriers (41.3 vs 47.9) and time to diagnosis of contralateral BC was shorter. BRCA1/2 carriers had significantly higher incidence of medullary BC (13.6% vs 1.7%). There was no difference in the incidence of other tumor pathology. BRCA1/2 carriers developed significantly more frequent ovarian cancer than non carriers 12/32 and 1/72 respectively. Conclusions: Patients with bilateral BC having BRCA mutations are significantly younger, than non carriers and time of developing of contralateral BC is shorter.They have significantly more frequent family history of BC and higher risk of developing of ovarian cancer. The differences in clinical aspects of BRCA carriers with bilateral BC, should be considered in clinical management. No significant financial relationships to disclose.