Study of Ashkenazi Jewish women suggests gene screening rethink

All Ashkenazi
Jewish women should be screened for high-cancer-risk genetic mutations from age
30, say scientists behind a study looking at that population.

In the
research, women who tested positive for dangerous mutations in the BRCA1 and
BRCA2 genes - which occur in relatively high frequency among Ashkenazi Jews - had high rates of breast and ovarian cancer, even with no
family history of the disease.

Speaking to The New York Times, Dr Ephrat
Levy-Lahad, senior author of the study and director of medical genetics at
Shaare Zedek Medical Center in Israel, voiced her support for BRCA screening
being offered as a universal test. 'We should be screening
people who are still healthy at a stage when we can prevent the disease',
she said.

In Israel, current
practice is to screen women for these mutations only if they have breast or
ovarian cancer or have a strong family history of the disease. Identifying
carrier status earlier can allow women to take preventive measures such as
mammography, physical examination, removal of the ovaries and fallopian tubes
or risk-reducing mastectomy.

In the study,
which is published in the journal PNAS, researchers screened over 8,000 healthy Ashkenazi Jewish men from out-patient
clinics for mutations in the BRCA1 and BRCA2 genes and then tested these men's female
relatives for the mutations. In this way 211 women with mutations were
identified. Of the women who reached aged 60, 60 percent of BRCA1 carriers and
one third of BRCA2 carriers had developed breast or ovarian cancer, although half
reported no family history of cancer.

Among
Ashkenazi Jews, 11 percent of breast cancers and 40 percent of ovarian cancers
are linked to mutations in the BRCA1 and BRCA2 genes. Professor Mary-Claire
King from the University of Washington, joint senior author of this study, helped
discover the BRCA1 gene in 1990.

Some
clinicians, however, are sceptical about the benefits of universal screening. Dr
Susan Domchek, from the Basser Research Center for BRCA at the University of
Pennsylvania, told the New York Times: 'I don't think this
resolves the question of what the risk is to someone with no family history and
a mutation'.

Speaking
about preventative removal of healthy breasts and ovaries Dr Domheck said: 'These
[procedures] are not trivial. They have potential to cause harm'.

The deputy chief medical officer
of the American Cancer Society, Dr Leonard Lichtenfeld, noted that the results
were thought-provoking but would have to be discussed extensively before there
was any change to screening practice. 'People who think they
should be tested really need to be appropriately counselled about the potential
benefits and potential risks', he told The New York
Times.