Risk of breast cancer mutations underestimated for Asian women, Stanford s...( STANFORD Calif. - Oncologist Allison...),Health

STANFORD, Calif. - Oncologist Allison Kurian, MD, and her colleagues at the Stanford University School of Medicine were perplexed. Computer models designed to identify women who might have dangerous genetic mutations that increase their risk of breast and ovarian cancer worked well for white women. But they seemed to be less reliable for another ethnic group.

"We've been repeatedly surprised when Asian women who the models predicted would probably not have the mutations do in fact have them," said Kurian. She recently showed that in a head-to-head comparison between whites and Asians, two of the most commonly used models failed in predicting the presence of mutations in almost half of the Asian women studied.

"Doctors and patients should have a higher level of suspicion when using these prediction models in Asian women, because they under-predicted the true number of clinically important mutations," said Kurian. "We may have to consider more subtle patterns of family cancer history when considering genetic testing in this ethnic group."

Kurian, assistant professor of oncology and of health research and policy, is the first author of the research, which was published online in the Journal of Clinical Oncology on Sept 8.

Mutations in two genes - BRCA1 and BRCA2 - are strongly associated with the development of breast or ovarian cancer in carriers. However, not every woman with a family history of cancer or who develops these cancers has these mutations.

To determine who should be tested for the mutations, genetic counselors frequently use computer models that assess specific variables for each woman, such as the number of relatives affected by breast and ovarian cancer, the age of each relative at onset of the condition and how closely the woman is related to her affected relatives. Those women deemed by the models to be likely carriers of these mutations are referred for testing of their BRCA1 and BRCA2 genes.
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