Abstract P4-10-13: Analyses of racial disparities in genetic testing and surgical management of patients with triple-negative breast cancer in the era of multigene panel testing
Authors: Gopalakrishnan D , Yanda C , Abbas H , Kline M , Stephens M , Grobmyer SR , Pederson HJ 
Published: February 2018

Background

Under-utilization of genetic counseling and testing among African-American (AA) women with breast cancer (BC) has been reported in previous studies, and there are concerns that disparities may widen with further genomic advances. Our objective was to compare AA and Caucasian (CC) patients with triple-negative breast cancer (TNBC) with regards to referral for genetic counseling, patterns of genetic testing, and patient-compliance with genetic counseling recommendations. We chose TNBC since a majority of these patients would qualify for genetic counseling ± testing. We also analyzed for differences between the two races in prevalence of deleterious BC-associated mutations, stage of BC on presentation, and surgical choices.

Methods

In this retrospective medical records-based observational study, we included all patients in our tumor registry with TNBC diagnosed between 09/01/2013 and 02/28/2017. Race, clinical characteristics and details pertaining to genetic counseling and testing were recorded. X2 test was used to compare categorical variables. A p-value &lt; 0.05 was considered significant.

Results

477 patients -358 CC and 96 AA- with TNBC were included. Mean age was 60.3 years. 331 patients met National Comprehensive Cancer Network (NCCN) criteria for genetic counseling - of these, 85.5% had genetic consult order placed, 72.8% attended counseling, and 71.9% underwent genetic testing (multigene panel testing 55.0%, BRCA 1/2 testing 39.9%, single-site testing 2.5%, and multisite-3 testing 2.5%). Between CC and AA, no significant differences were found in the proportion of qualifying patients who had referral for genetic counseling (84.7 vs 87.7%, p=0.562), attended counseling (72.2% vs 73.7%, p=0.816), or underwent genetic testing (72.1% vs 70.1%, p=0.764). The choices of type of genetic tests were also not significantly different between the two groups (p=0.349). Though the prevalence of highly penetrant mutations in breast cancer-associated genes trended to be higher among CC than AA (14.1% vs 9.5%), this difference did not reach statistical significance (p=0.429). In our population, stage of TNBC at presentation was comparable between the two races – 80.4% of CC presented with stage I or II disease compared to 80.2% of AA (p=0.931). The two groups were also comparable with regards to the choices of breast surgery and reconstruction, as shown in the table.

  CaucasiansAfrican-Americansp-valueSurgery TypePartial Mastectomy154(47.4%)38(44.7%)0.317 Unilateral Mastectomy101(31.1%)35(41.2%) Bilateral Mastectomy70(21.5%)12(14.1%)ReconstructionYes96(56.1%)24(51.1%)0.535 No75(43.9%)23(48.9%)Reconstruction TypeImplant87(90.6%)19(79.2%)0.118 Tissue Flap9(9.4%)5(20.8%)

Conclusions

Contrary to previous reports, in this cohort of TNBC patients, we did not identify significant disparities between AA and CC in patterns of referral for genetic counseling, in patient compliance with testing or in type of testing performed. Also, no significant differences were found between the two races in choices of breast surgery or reconstruction. As a caveat, with an overall insured rate of ˜97% across our network, the uninsured population may have been under-represented by our cohort.

Citation Format: Gopalakrishnan D, Yanda C, Abbas H, Kline M, Stephens M, Grobmyer SR, Pederson HJ. Analyses of racial disparities in genetic testing and surgical management of patients with triple-negative breast cancer in the era of multigene panel testing [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-10-13.