March 06, 2019, 03:17 pm Chris Crawford – Mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 are just one of many factors that can greatly increase a woman's risk of developing certain cancers, such as breast and ovarian cancer. One important step in preventing these cancers is to help women understand their risk.
On Jan. 15, the U.S. Preventive Services Task Force (USPSTF) posted a draft recommendation statement and draft evidence review on risk assessment, genetic counseling and genetic testing for BRCA-related cancer in women.
Based on its review of the evidence, the USPSTF recommended that physicians screen women who have family members with breast, ovarian, tubal or peritoneal cancer or who have an ethnicity or ancestry associated with BRCA1 or BRCA2 gene mutations with one of several screening tools designed to identify a family history that may be associated with an increased risk for potentially harmful mutations in these breast cancer susceptibility genes, the draft recommendation said.
Women with positive screening results should receive genetic counseling and, if indicated after counseling, genetic testing, the USPSTF said.
All of this guidance received the task force's "B" recommendation grade.
"BRCA testing is beneficial for the small number of women in the United States who are at increased risk for BRCA1 or BRCA2 mutations," said USPSTF member Carol Mangione, M.D., M.S.P.H., in a news release. "The test results are complex, and testing comes with some harms, so we recommend women who get tested meet with a licensed genetic counselor who can guide them through the process."
Mutations of the BRCA genes are estimated to occur in one in 300 to 500 women in the general population and account for 5 percent to 10 percent of breast cancer cases and 15 percent of ovarian cancer cases, the draft recommendation said.
The task force recommended against routine screening, genetic counseling or genetic testing for women whose family or personal history, ethnicity or ancestry is not associated with an increased risk for potentially harmful mutations in the BRCA1 or BRCA2 gene; this is a "D" recommendation.
Women with positive screening results should receive genetic counseling from a licensed counselor who will analyze the patient's family history and conduct a more in-depth risk assessment, the USPSTF said.
The counseling session also includes a thorough explanation of the benefits and harms of genetic testing and options for what to do if the test results show a BRCA mutation that is associated with an increased risk of cancer. If a counselor determines that a woman's family history or ancestry or ethnicity suggests she is at increased risk for BRCA-related mutations, the counselor should offer testing.
This draft recommendation statement is consistent with the USPSTF's 2013 final recommendation, which the AAFP supported at the time.
Since 2013, the validity of genetic testing for BRCA mutations has been established and the potential benefits and harms of previously reviewed interventions, such as risk-reducing medications and surgery, have been studied for longer follow-up periods, the draft recommendation noted.
In addition, there have been more studies of newer imaging techniques (breast MRI), surgical procedures (salpingo-oophorectomy rather than oophorectomy alone) and medications (aromatase inhibitors), the USPSTF said.
To update its 2013 recommendation, the USPSTF commissioned a systematic review on risk assessment, genetic counseling and genetic testing for potentially harmful BRCA1 or BRCA2 mutations in asymptomatic women who have never been diagnosed with BRCA-related cancer, as well as those with a previous breast, ovarian or peritoneal cancer diagnosis; women who have completed treatment; and women who are considered cancer-free.
The task force said it also reviewed interventions aimed at reducing the risk for BRCA-related cancer in women with potentially harmful BRCA mutations, including intensive cancer screening (e.g., earlier and more frequent mammography or breast MRI), medications (e.g., tamoxifen, raloxifene or aromatase inhibitors) and risk-reducing surgery (e.g., mastectomy or salpingo-oophorectomy).
The USPSTF found that tools that have been validated in studies and are clinically useful predictors of which individuals should be referred for genetic counseling include the Ontario Family History Assessment Tool, Manchester Scoring System, Referral Screening Tool, Pedigree Assessment Tool, FHS-7 and the International Breast Cancer Intervention Study instrument. All of these tools have sensitivity estimates between 77 percent and 100 percent.
The task force reviewed 28 studies on pretest counseling that reported measures of distress associated with genetic counseling for BRCA-related cancer, including cancer worry, anxiety and depression. "In general, pretest genetic counseling either decreased or had no effect on breast cancer worry, anxiety and depression," the draft recommendation said.
Twenty-two studies examined risk perception, with most reporting either improved risk perception or no association, one study reporting decreased perception and one study reporting mixed results.
Finally, five studies that evaluated the effects of genetic counseling on BRCA mutation testing intention found decreased intent to test in four studies and increased intent in one study.
The USPSTF found no studies on the benefits of post-test counseling.
Beulette Hooks, M.D., of Midland, Ga., chair of the Commission on Health of the Public and Science, told AAFP News that starting at age 21, she asks female patients if they have a family history of breast and/or ovarian cancer.
"If the patient is not sure, I encourage them to see what has been going on in their family," she said.
When Hooks confirms there may be a history of cancer in the family (grandmother, aunts, mother or sisters), she sends them for genetic counseling.
"If the counseling suggests a possible mutation, the testing is done," she said. "The counseling entails a very detailed family tree that identifies the cancers in the family, especially breast and ovarian (including breast cancer in males)."
In addition to people of Ashkenazi Jewish descent, who are known to have a higher prevalence of harmful BRCA1 and BRCA2 mutations than people in the general U.S. population, said Hooks, "other ethnic and geographic populations around the world, such as the Norwegian, Dutch and Icelandic peoples, also have a higher prevalence of specific harmful BRCA1 and BRCA2 mutations."
The USPSTF is accepting comments on its draft recommendation statement and draft evidence review on screening, testing and counseling for BRCA-related cancer until 8 p.m. EDT on March 18. All comments received will be considered as the task force prepares its final recommendation.
The AAFP will review the USPSTF's draft recommendation statement and supporting evidence and will provide comments to the task force. The Academy will release its own recommendation on the topic after the task force finalizes its guidance.