Utilization of Genetic Testing Among Commercially Insured Patients With Ovarian Cancer
Although guidelines recommend universal germline BRCA testing for patients with ovarian cancer, the annual rate of testing has ranged from 10% to 30%. Little research has assessed this rate in commercially insured patients or has identified characteristics associated with rates of testing.
To measure this rate, researchers at the Dana-Farber Cancer Institute used the database of a large, national, commercial insurer to identify patients with claims for ovarian, fallopian, or primary peritoneal cancer who received carboplatin or cisplatin chemotherapy within 6 months of biopsy or surgery between 2008 and 2018 (JAMA Network Open. 2022;5(1):e2142703. doi:10.1001/jamanetworkopen.2021.42703). They excluded patients without surgery or outpatient visits, who had <12 months of continuous insurance, whose zip codes were missing, or who were aged <18 years. Moreover, they used outpatient evaluation and management claims with a diagnosis ≤6 months from the first outpatient claim for chemotherapy to attribute patients to practices and physicians.
The primary outcome of the study was germline BRCA testing based on gene-specific and method-based procedure codes. Secondary outcomes were testing timeliness, defined as testing ≤6 months from biopsy or surgery, and median time from first chemotherapy claim to testing.
The researchers used chi-square tests and linear regression applied with SAS statistical software version 14.1 to assess characteristics associated with outcomes; they considered results with a two-sided P≤0.05 to be statistically significant.
As a result, they found that 1220, or 34% of the 3603 women with ovarian cancer studied, received germline BRCA testing. The mean age of the study group was 57 years (standard deviation, 11.3 yr). From 2008 to 2018, rates of testing increased from 15% (55/375 patients) to 46% (96/207 patients), and median time to testing decreased from 280 days to 73 days.
Results of adjusted analysis revealed that rates of testing were almost 21 percentage points lower for older women (those aged ≥65 years) than for those aged <50 years (95% confidence interval [CI], -25.8 to -16.4 percentage points). Furthermore, rates of testing were nearly 5 percentage points lower (95% CI, -8.9 to -0.2 percentage points) for women with more vs. less comorbidities (Charlson Comorbidity Index score ≥2 vs 0).
In addition, the researchers found similar rates of testing among oncologists whether they were medical or gynecologic but lower rates of testing in other types of physicians vs. gynecologic oncologists (−5.9 percentage points, 95% CI, −10.3 to −1.5 percentage points).
However, the rate of testing was higher at academic and National Cancer Institute (NCI) cancer centers than in community practices. “Nearly 80% of patients received care in community practices, where rates were statistically lower,” wrote Alexi Wright, MD, MPH., Division of Population Sciences, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
The rate of testing increased over time; the adjusted difference in the rate for 2018 vs. that for 2008 was 32 percentage points (95% CI, 24 to 40 percentage points). Nevertheless, the rate stayed at <50% in most years. The researchers found similar results for their analyses of the timeliness of germline BRCA testing; this outcome improved to a statistically significant degree from 2008 to 2018.
“Interventions targeting clinicians are essential because the absence of physician recommendations remains the largest barrier to testing,” noted Dr. Wright and team.
