- 8% of patients with breast cancer and 15% of patients with ovarian cancer have actionable genetic variants, according to a Surveillance Epidemiology and End Results (SEER) analysis linked to genetic testing results.
- Only about one-quarter of those with breast cancer and one-third with ovarian cancer undergo genetic testing.
Why this matters
- Testing rates are well below levels associated with current clinical guidelines.
- Population-based cohort of 77,085 patients with breast cancer and 6001 with ovarian cancer in California and Georgia (2013-2014) and reported to the SEER database.
- Data were linked to genetic test results from 4 laboratories that performed nearly all genetic testing.
- Funding: NIH.
- 24.1% of breast cancers and 30.9% with ovarian cancer had genetic test results.
- Testing for ovarian cancer was lower in blacks (21.6% vs 33.8% whites) and uninsured patients (20.8% vs 35.3% insured).
- Most prevalent pathogenic variants:
- Breast cancer: BRCA1 (3.2%), BRCA2 (3.1%), CHEK2 (1.6%), PALB2 (0.96%), ATM (0.73%), and NBN (0.35%).
- Ovarian cancer: BRCA1 (8.7%), BRCA2 (5.8%), CHEK2 (1.4%), BRIP1 (0.92%), MSH2 (0.79%), and ATM (0.64%).
- Racial/ethnic differences were observed for BRCA1 (ovarian cancer: whites, 7.2% vs 16.1% in Hispanics) and CHEK2 (breast cancer: whites, 2.3% vs 0.15% blacks).
- Potential testing bias.