Genetic Testing in Ovarian and Breast Cancer
Posted: Monday, April 22, 2019
Women with breast and ovarian cancers are “dramatically” undertested for genetic variants associated with disease, according to a real-world study of more than 83,000 patients in California and Georgia. The study was published in the Journal of Clinical Oncology by Allison W. Kurian, MD, MSc, of Stanford University, and colleagues. Moreover, between 8% and 15% of those with breast or ovarian cancer had “cancer-associated mutations that could be used to drive care decision and influence family members’ health care and screening choices,” stated Dr. Kurian in a Stanford press release.
The study included all women aged 20 or older who were diagnosed with breast or ovarian cancer in the Georgia or California Surveillance, Epidemiology, and End Results (SEER) registries in 2013 and 2014. This came to 77,085 patients with breast cancer and 6,001 patients with ovarian cancer. The authors linked these data to records from the four major laboratories that processed the genetic tests to confirm the genetic results.
A total of 24% of patients with breast cancer and 31% of patients with ovarian cancer received genetic testing. The prevalence of ovarian cancer testing was lower in black patients (22%) than in non-Hispanic white patients (34%). Genetic testing revealed that 8% of tested patients with breast cancer and 15% of those with ovarian cancer had actionable disease-associated genetic variants. The patients were not a random sample, so the prevalence of these variants in the population may differ.
The study showed little regional variation despite including two different states, suggesting that the results may be generalizable to other states. The rates of ovarian cancer genetic testing are too low at 31%, according to the authors. National guidelines recommend testing all patients with high-grade serous ovarian cancer. The authors also argue that 100% of women younger than age 45 who are diagnosed with breast cancer should undergo genetic testing.
Disclosure: The study authors’ disclosure information may be found at ascopubs.org.