Racial and Ethnic Differences in BRCA1/2 and Multigene Panel Testing Among Young Breast Cancer Patients

T Jones,X Jiang,Ms Trivedi,Wk Chung,T Silverman,M Underhill,R Kukafka,Kd Crew

doi:10.1007/s13187-019-01646-8

Abstract

Genetic testing for hereditary breast and ovarian cancer (HBOC) is recommended for breast cancer patients diagnosed at age ≤ 50 years. Our objective was to examine racial/ethnic differences in genetic testing frequency and results among diverse breast cancer patients. A retrospective cohort study among women diagnosed with breast cancer at age ≤ 50 years from January 2007 to December 2017 at Columbia University in New York, NY. Among 1503 diverse young breast cancer patients, nearly half (46.2%) completed HBOC genetic testing. Genetic testing completion was associated with younger age, family history of breast cancer, and earlier stage, but not race/ethnicity or health insurance status. Blacks had the highest frequency of pathogenic/likely pathogenic (P/LP) variants (18.6%), and Hispanics and Asians had the most variants of uncertain significance (VUS), 19.0% and 21.9%, respectively. The percentage of women undergoing genetic testing increased over time from 15.3% in 2007 to a peak of 72.8% in 2015. Over the same time period, there was a significant increase in P/LP and VUS results. Due to uncertainty about the clinical implications of P/LP variants in moderate penetrance genes and VUSs, our findings underscore the need for targeted genetic counseling education, particularly among young minority breast cancer patients.

Highlights

Germline genetic testing is the recommended standard of care for young breast cancer patients diagnosed at age ≤ 50 years due to an increased risk of hereditary breast and ovarian cancer (HBOC) syndrome [1]
A total of 1621 patients with breast cancer diagnosed at age 50 years or younger between 2007 and 2017 at Columbia University Irving Medical Center (CUIMC) were identified, and 118 patients were excluded from the study, including 94 (5.8%) with lobular carcinoma in situ, 19 (1.2%) with no available electronic health record (EHR) data at CUIMC, and 5 (0.3%) males
We examined frequency and predictors of completion of BRCA1/2 and multigene panel testing and assessed racial/ ethnic differences in genetic testing frequency and results among breast cancer patients diagnosed at age ≤ 50 years

Summary

Introduction

Germline genetic testing is the recommended standard of care for young breast cancer patients diagnosed at age ≤ 50 years due to an increased risk of hereditary breast and ovarian cancer (HBOC) syndrome [1]. Numerous other high-penetrance genes such as CDH1, PTEN, STK11, TP53, and PALB2 are associated with hereditary breast cancer, making multigene panel testing for hereditary cancer risk of critical importance in young breast cancer patients [3]. Multigene panel testing offers more comprehensive cancer risk assessment, there is greater uncertainty in clinical decision-making due to increased likelihood of variants of uncertain significance (VUS), among racial/ethnic minorities who have been found to have more frequent VUS results compared to non-Hispanic Whites [4]. Young breast cancer patients are more likely to be diagnosed with triple-negative breast cancer (TNBC), which is associated with a higher frequency of

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