Abstract PD6-12: Evaluating racial disparities in breast cancer referrals for hereditary risk assessment
Authors: Pepin A , Peterson J , Thomas R , Johnson K , Stark E , Biagi T , Kaltman R 
Published: May 2019

Background: There is a pronounced onco-racial disparity in Washington, D.C., which had the highest national incidence of breast cancer in African Americans (AA) patients in between 2010-2015 and the worst outcomes (American Cancer Society). Recent data indicates a higher incidence of deleterious BRCA1 [and BRCA2] mutations and variants of uncertain significance (VUS) in AA patients compared to Caucasian (C) patients when controlled for patients of Ashkenazi Jewish (AJ) populations (Hall 2009). Despite this, AA women meeting National Comprehensive Cancer Network (NCCN) criteria for genetic testing are less likely to complete such testing compared to C women nationally. Studies have investigated psycho-social drivers of minority patient aversion to genetic testing. We hypothesize that lack of physician referral for cancer genetic counseling and testing for AA women contributes to this disparity.

Methods: The George Washington Cancer Center (GWCC) Registry was used to identify non-Hispanic African Americans (BNH) and non-Hispanic whites (WNH) treated for breast cancer between 2014-2018. Of those individuals selected for inclusion were those who met select NCCN criteria for referral for genetic evaluation including breast cancer diagnosis under age 50, triple negative breast cancer (TNBC) under age 60, and two primary breast cancers. Only BNH and WNH individuals were included. Excluded patients were those who were not BNH or WNH or who did not meet the NCCN criteria listed above. Patients were then stratified by race according to who underwent genetic evaluation, whether at our Ruth Paul Cancer Genetics and Prevention Service (RPCGPS) or elsewhere, by reviewing GWCC, RPCGPS, and patient clinic records for genetic testing results from outside institutions. Patient charts were used to identify individuals who received a physician referral over the course of their cancer care.

Results: 1180 patients were treated at the GWCC for breast cancer (both in situ and invasive carcinoma) between 2014–2018. Of those, BNH n=502; WNH n=435. Twenty-seven percent of BNH and WNH patients met the study criteria for referral for genetic evaluation (n=252; BNH n=115, WNH n=137), including breast cancer diagnosis under age 50 (BNH n=76; WNH n=108), TNBC under age 60 (BNH n=14; WNH n=5), and two primary breast cancers (BNH n=18, WNH n=16). Several patients identified met two or more criteria for referral (BNH n=7, WNH n=8). Physician referral rates differed significantly by race (BNH 76%, n=87 and WNH 91%; n=125; χ2=11.4, p-value&lt;0.001). Of referred patients, there was no significant difference in those who followed-up at RPCGPS by race (BNH 93%, n=81; WNH= 93%, n=116, χ2 =0.0072, p-value=0.93).

Conclusions: Low genetic testing rates for AA breast cancer patients are an impediment to resolving the prominent onco-racial breast cancer disparities. This study identified physician referral as a potential contributor to racial disparity in the utilization of cancer genetics services. Potential reasons for the discrepancy in referral may include lag in physician education on the topic of hereditary risk and barriers in physician-patient communication. These findings need to be confirmed and explored at other sites to help improve the identification of at-risk women in the AA community.

Citation Format: Pepin A, Peterson J, Thomas R, Johnson K, Stark E, Biagi T, Kaltman R. Evaluating racial disparities in breast cancer referrals for hereditary risk assessment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-12.