Doctors should screen women with a family history of breast or ovarian cancer to see if the cancers might be due to certain mutations - and if so, women should be counseled about their personal risks before getting tested, a government-backed panel said this week.
One in 300 to one in 500 women has a BRCA mutation. According to the National Cancer Institute, a woman's chance of getting breast cancer during her lifetime increases from 12 to 60 percent if she carries the mutation, and ovarian cancer from 1.4 percent to between 15 and 40 percent.
The new guidelines, from the U.S. Preventive Services Task Force, are in draft form and will be available for public comment through April 29 here:.
The panel said there is no benefit - and potential harm - in testing women for mutations if they have no family history of cancer or if their family history doesn't suggest an underlying genetic cause.
"The message for most people is, ‘This test is not going to benefit you in any way,'" said Dr. Virginia Moyer, chair of the USPSTF and a professor at Baylor College of Medicine in Houston.
"But for women who do have a family history, it's clear there is a benefit if you winnow it down to the right people," she told Reuters Health.
To determine if a family history of cancer is likely tied to BRCA mutations, doctors use a standardized questionnaire that addresses the number of relatives a woman has with cancer and the age at which they were diagnosed, among other factors.
If women are referred for genetic counseling, they still have to decide whether or not to be tested. That's not an easy choice, Moyer said, because test results aren't always clear cut.
"Part of the problem is an awful lot of the time what you find out is nothing," she said. "You find out, ‘Well, maybe.' And that's a very uncomfortable place to be."
Women who are found to carry BRCA mutations have a number of options to reduce their risk of breast or ovarian cancer, but most haven't been well studied - and each can cause side effects or complications.
For example, they can undergo frequent screening, take estrogen-blocking drugs such as tamoxifen or have their breasts and ovaries surgically removed.
The panel did not make a recommendation about which of those options is best, concluding that more research is needed to determine the benefits and potential harms of each intervention.
"The options right now for things that we know are going to be effective are pretty extreme," such as mastectomy, Moyer said.
Her group's draft guidelines are based on an analysis of past studies suggesting genetic counseling may ease anxiety and depression among women and improve how accurately they interpret their own cancer risks.
They echo the panel's recommendations on BRCA counseling and testing from 2005.
Ellen Matloff, director of cancer genetic counseling at the Yale Cancer Center in New Haven, Connecticut, said she hopes future recommendations will cover counseling for BRCA mutations in men - who are also at risk of getting mutation-related cancers or passing the mutations on to their children.
"It's really important that we once and for all eliminate the notion that only women carry these mutations," she said.
Genetic counseling could also be important for people with a newly-diagnosed cancer who are trying to make treatment choices, or for cancer survivors who may be prone to future disease, Matloff added.
Among people at risk for carrying a mutation linked to cancer, she agreed with the USPSTF that an in-depth family history and risk assessment should be done before offering genetic testing.
"It's a pretty detailed conversation," Matloff, who wasn't involved in the new guidelines, told Reuters Health.
"Knowing your own personal and family history and getting advice about whether the cancers in your family are hereditary is really critical. And (so is seeing) a certified genetic counselor to get that information," she said.