BRCA+ test result impact and timing on surgical treatment decisions for patients with breast cancer.

Abstract

626 Background: In a study of insurance claims data we found BRCA mutation analysis performed before breast cancer surgery affected surgical approach (Trosman JR, ASCO-Abstract-666-2010). Patients with BRCA mutation have a higher risk of breast cancer recurrence. These patients are more likely to view mastectomy as the best way to reduce future BC recurrence while avoiding multiple surgeries and radiation (Schwartz, JCO-2004). The goal of this study is evaluation of BRCA test result impact on BC surgical decisions. Methods: This is a retrospective review of medical records and insurance claims for 302 breast cancer patients who underwent BRCA testing and definitive surgery between 07/01/2006 and 09/30/2010. Following an IRB approved protocol; we used simple frequencies and Fisher's exact test to evaluate occurrences of BRCA test results relative to surgical timing and decisions. Results: The BRCA test was performed pre-surgery in 37% (112/302) of this cohort. The majority of women, 71% (79/112), tested pre-surgery had a mastectomy compared to 38% (73/190) of women tested after surgery (p=.0001). Of women with BRCA positive results, 83% (19/23) tested pre-surgery had a mastectomy compared to 44% (17/39) of women tested after surgery (p=.0003). There was a significant trend toward bi-lateral mastectomy in the pre-surgery BRCA+ woman (13/23) as compared to (7/39) of the BRCA+ women tested after surgery (p=.004). Of women with known negative BRCA results, 70% (39/56) tested pre-surgery had a mastectomy compared to 36% (34/94) of women tested after surgery (p=.0001). Conclusions: Most women with positive BRCA test results prior to surgery chose mastectomy, a majority had double mastectomies. Less than half of women with positive BRCA results after surgery chose mastectomies. Conducting BRCA mutation analysis prior to breast cancer surgery is associated with a more radical surgical approach. Interestingly, women with known negative BRCA results were more likely to choose mastectomies than women without BRCA test results. Further research is needed to investigate how known factors such as BRCA results, experience of genetic counseling, and awareness of risks based on family history impact surgical decisions.