Gene cancer tests 'need review'

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Decisions over who to test for a high-risk breast cancer gene should not be made solely on the basis of family history, US research suggests.

Predictions as to whether a woman may develop hereditary breast cancer are often reached by counting the number of female relatives with the disease.

But this excludes women who do not have many female relatives in whom the disease could have manifested itself.

The Journal of American Medicine study said testing criteria needed reviewing.

The study looked at 306 women who had breast cancer and, crucially, no close female relatives with the disease.

BRCA genes were found in 13.7% of those with few close female relatives in the first place, compared with 5.2% in those with more than two.

The genes BRCA1 and BRCA2 account for about 10% of inherited breast cancers, and they are also associated with an increased risk of ovarian cancer.

The researchers noted that identifying women who have had BRCA-associated breast cancer is important because the risk of a new primary breast cancer appearing is high.

'Overlooked'

Researchers said they hoped the study could lead to a re-evaluation of when to refer women for BRCA testing.

The findings suggest that guidelines on who should be tested should be more inclusive of these women Ruth YatesCancer Research UK

A number of models used to predict whether a woman may develop breast cancer count the number of close relatives with cancer, and make no adjustment for the "missing value" inherent for women who do not have those relatives in the first place.

"Cancer risk assessment practices and genetic testing guidelines need to be more inclusive of single cases of breast cancer when there is limited family structure," the authors wrote.

Cancer Research UK welcomed the study.

"This research shows that women with fewer first degree female relatives are being overlooked for BRCA testing," said Ruth Yates, Cancer Research UK's head of statistical information.

"The findings suggest that guidelines on who should be tested should be more inclusive of these women. We welcome research that better enables us to identify those most at risk of breast cancer."

Lisa Grosser, clinical nurse specialist at Breast Cancer Care, said the research raised some "interesting issues".

"There is still much to learn with regards to genetically linked breast cancer and we would welcome further study to build on the work presented here.

"It should be remembered that only five to 10% of breast cancer is due to inherited factors."