Identifying disparities in germline and somatic testing for ovarian cancer

Germline mutations occur in approximately 25% of patients with epithelial ovarian cancers while somatic BRCA mutations are estimated at 5-7%. The objectives of this study were to determine the rate of germline and somatic testing in women with ovarian cancer and to identify disparities in testing at a comprehensive cancer center (CCC) and a safety net hospital (SNH).

Patients treated for ovarian cancer from 2011 to 2016 were included. Clinicopathologic data were abstracted from the electronic medical records. Logistic regression modeling were performed to calculate odds ratios (OR) and corresponding 95% confidence intervals (95%CI).

Out of 367 women, 55.3% completed germline testing; 27.0% received somatic testing. Women at the CCC were more likely to be tested for germline (60.4% vs 38.1%, p ≤ 0.001) and somatic (34.3% vs 2.4%, p ≤ 0.001) mutations than those at the SNH. Patients with Medicare (aOR = 0.51, 95%CI 0.28-0.94, p = 0.032) or Medicaid (aOR = 0.42, 95%CI 0.18-0.99, p = 0.048) were less likely to receive germline testing than those privately insured. Patients with Medicaid were less likely to receive somatic testing (aOR = 0.15, 95%CI 0.04-0.62, p = 0.009) than those privately insured. Women with disease recurrence had a higher likelihood of being tested for germline (OR = 3.64, 95%CI 1.94-6.83, P < 0.001) and somatic (OR = 7.89, 95%CI 3.41-18.23, p < 0.001) mutations. There was no difference in germline or somatic testing by race/ethnicity.

Disparities in both germline and somatic testing exist. Understanding and overcoming barriers to testing may improve cancer-related mortality by allowing for more tailored treatments as well as for improved cascade testing.