In a study reported in the Journal of Clinical Oncology, Talia Golan, MD, and colleagues identified geographic and ethnic heterogeneity of germline BRCA1/2 mutation prevalence among patients screened for entry into the phase III POLO trial, which examined the efficacy of olaparib maintenance treatment in those with metastatic pancreatic cancer.
Talia Golan, MD
The study involved data from the first 2,206 patients screened for eligibility to enter the POLO trial.
Key Findings
Among 2,167 patients with previously unknown germline BRCA1/2 mutation status, 128 (5.9%) had a newly identified germline BRCA1/2 mutation. Rates of newly identified germline BRCA1/2 mutations were highest in the United States (9.5%), France (7.6%), and Israel (7.4%).
Including patients with a known germline BRCA1/2 mutation, the prevalence of germline BRCA1/2 mutation was 7.2%. The prevalence was 5.8% when analysis excluded the United States and Israel, which have populations enriched in Ashkenazi Jews (known to have high rates of BRCA1 and BRCA2 founder mutations).
“We identified substantial geographic and some racial variability in germline BRCA1/2 mutation prevalence among patients with [metastatic pancreatic cancer], an important consideration given the increased use of familial screening and possible future use of targeted therapies in this setting."— Talia Golan, MD, and colleagues
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Patients with a germline BRCA1/2 mutation were younger (mean age = 57.9 vs 61.1 years) and more likely to have early-onset disease (21.5% vs 13.9% at < 50 years) than those without. Prevalence of germline BRCA1/2 mutations did not differ by sex.
Higher newly identified germline BRCA1/2 mutation prevalence was observed among African American (10.7% of 28 with unknown status) vs white (6.1% of 1,808), Asian (5.0% of 218), and other (1.6% of 61) patients.
Of 139 white patients with a germline BRCA1/2 mutation, 110 were newly identified during screening; the majority of germline BRCA1/2 mutations in African American (3 of 4), Asian (11 of 11), and Hispanic patients (5 of 5) were also newly identified.
The investigators concluded, “We identified substantial geographic and some racial variability in germline BRCA1/2 mutation prevalence among patients with [metastatic pancreatic cancer], an important consideration given the increased use of familial screening and possible future use of targeted therapies in this setting. Although our study included small numbers of nonwhite patients, prior knowledge of their [mutation] status was limited compared with their white counterparts, which suggests disparities in genetic testing uptake.”
Dr. Golan, of Sheba Medical Center at Tel-HaShomer, Tel Aviv University, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by AstraZeneca. For full disclosures of the study authors, visit ascopubs.org.
