Most women with history of breast or ovarian cancer don't get genetic testing

More than four out of five women in the United States who've had breast or ovarian cancer have not had genetic testing or even discussed genetic testing with a health care provider. This amounts to an estimated 1.2 to 1.3 million patients who could have been tested but weren't, according to the results of a recent study published in the Journal of Clinical Oncology.

Large national efforts are needed to address this unmet need, the authors stated.

Christopher Childers, MD, Department of Surgery at UCLA's

David Geffen School of Medicine, Los Angeles, CA

"Many of these women have inherited genetic changes that put them and their family members at risk for future cancers," said lead author Christopher Childers, MD, a resident physician in the Department of Surgery at UCLA's David Geffen School of Medicine, in Los Angeles, CA.

"Identifying a mutation is often important for surgical decision-making and cancer therapy, but its importance extends further than that," he added. "If individuals are aware that they have these mutations, they can take steps to lower their future cancer risk."

Nearly 4 million women in the US have a history of breast or ovarian cancer. Of these, up to 10% of breast cancers and 15% of ovarian cancers can be attributed to hereditable mutations, most commonly BRCA1 or BRCA2 mutations. Genetic testing for BRCA1 and BRCA2 has been available since the mid-1990s. But until now, no one knew the number of patients at high risk for these mutations who had not been tested.

For this study, Dr. Childers and colleagues reviewed data sets from the 2005, 2010, and 2015 National Health Interview Surveys. The subjects they selected for their study included adult women with a history of breast or ovarian cancer who met 2017 National Comprehensive Cancer Network (NCCN) eligibility criteria.

Of 47,218 women, 2.7% had a history of breast cancer. Among those who met at least one of the eligibility criteria, 29% had discussed genetic testing with a health care provider, 20.2% were advised to undergo genetic testing, and only 15.3% had been tested.

In addition, 0.4% of the 47,218 women had a history of ovarian cancer. Of those who were eligible, 15.1% had discussed, 13.1% were advised to undergo, and 10.5% underwent genetic testing.

Based on these numbers, the researchers estimated that 1.2 to 1.3 million women with a history of breast or ovarian cancer had not undergone genetic testing "despite evidence-based guidelines supporting this as the standard of care," they wrote.

The researchers also determined that 75 out of every 100 eligible patients with a history of breast or ovarian cancer never discussed genetic testing with a health care provider. An additional 7 patients are lost between discussing and advising, and 4 more between advising and testing. These gaps reflect a lack of patient identification and perhaps a lack of provider awareness and knowledge, the researchers noted.

"Many women are not receiving vital information that can aid with cancer prevention and early detection for them and their family," said co-author Kimberly Childers, MS, a licensed and certified genetic counselor and the regional manager of the Providence Center for Clinical Genetics and Genomics, in Los Angeles, CA. "Thus, we have identified an incredible unmet need for genetic testing across the country."

The authors acknowledged that their study has some limitations, including that subjects' data was self-reported and not verified by medical records, and that subjects may not have accurately remembered whether they discussed, took, or were advised to take genetic testing.

"Future research should focus on understanding the characteristics of the eligible population that has not been tested, with an emphasis on measures of access to care," the authors concluded. "Further research should also assess the patient and provider factors that contribute to decreasing rates of patients discussing, being advised to undergo, and actually undergoing genetic testing."