Population screening to find women carrying mutated BRCA genes is a "questionable" idea given the "extraordinarily low prevalence," says an opinion-leading article published in JAMA Oncology.

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The researchers say that for every 10,000 women screened for BRCA gene mutations, only four cases of breast cancer and two cases of ovarian cancer will be prevented.

The viewpoint has been written by Dr. Patricia Ganz, a director of cancer research at the Jonsson Comprehensive Cancer Center of the University of California-Los Angeles (UCLA), and Elisa Long, PhD, assistant professor at the Anderson School of Management, also at UCLA.

They calculate that for every 10,000 women screened, BRCA testing - compared with family history-based testing - would prevent four cases of breast cancer and two cases of ovarian cancer. Dr. Ganz says:

"The cost of BRCA testing would need to drop by 90% for testing to be cost-effective for the whole population."

The authors add that the impact of BRCA screening would be to extend patients' lives by an average of only 2 days.

There would be no benefit for almost all women undergoing BRCA testing, according to the authors. For the 99.75% receiving a negative genetic test, it would not mean any increase in life expectancy.

The screen would not eliminate the need for regular mammograms either, and could provide false reassurance. The article concludes:

"Even though a very small percentage of women would benefit from universal BRCA testing, at $2000 to $4000 per test, such a strategy is an inefficient use of health care resources."

Of the 233,000 breast cancers diagnosed annually in the US, BRCA gene mutations account for 5-10%, although the cases usually develop at a younger age, often in both breasts, and often as a more aggressive subtype such as triple-negative breast cancer.

Affordable in the future?

The US Preventive Services Task Force (USPSTF) recommend BRCA genetic testing - which is most commonly done with the Myriad test - only if there is a known family history of breast, ovarian, tubal or peritoneal cancer.

Dr. Long says a new $249 test recently announced by Color Genomics could encourage other companies to introduce lower-cost genetic tests and make universal screening more practical and more affordable.

Providing personalized genetic counseling services on such a large scale, though, would not be practical.

"It's like looking for a needle in a haystack," says Dr. Long. "If only 1 in 400 women across the country have one or both of the BRCA-1 or BRCA-2 mutations, universal screening would cost $1 million to $2 million to detect a single BRCA mutation, or nearly $400 billion to screen all women in the US."

Dr. Long - who carries the BRCA1 mutation herself and has recently survived triple-negative breast cancer - says there are better alternatives:

"Perhaps this money could be better spent on other diagnostic tools for young women, such as MRIs [magnetic resonance imaging], to have the greatest impact."

"On a personal level," she adds, "I would have benefitted tremendously from universal BRCA testing, because I had no family history of breast cancer. But as a health services researcher, I must also consider the relative value of different medical interventions."

"Many patients wish to know more about their genetic risk factors," she continues, "and as more firms begin to offer genetic testing, we should expect the price to decrease, eventually making this an affordable policy."