Tuesday, April 29, 2008

Genes load cancer dice against black people

When I first saw this article inside NewScientist magazine my first thoughts were ‘genes being racist?’ However it turned out to be an interesting piece of information. Did you know that prostate and breast cancers are more deadly for African Americans than say white people? In the US around 60 percent of black men are more likely to develop prostate cancer, and twice as likely to die from it. The differences in the activity of key genes may be partly to blame. Until now, social and economic factors such as access to healthcare have been blamed. However at the annual meeting for Cancer Research of the American Association in San Diego, California, on April 15, Tiffany Wallace of the US National Cancer Institute in Bethesda, Maryland, implicated biological differences between the tumours of blacks and whites. 160 genes differing in activity between blacks and whites were found in screened prostate tumours removed from 33 African American and 36 white patients by Wallace and her colleagues.
The differences could indicate that tumours are more inflamed in black people. However some genes that were identified govern production of interferons, which defend against viruses. Therefore it’s possible the extra cases of prostate cancer in African Americans could be due to a higher rate of infection with an unknown cancer-causing virus. This is now undergoing investigation and whether if it is the case.
Meanwhile, African American women are slightly less likely to develop breast cancer than whites – however it often strikes them at a younger age and is more lethal. Lori Field of the Windber Research Institute in Pennsylvania compared breast tumours taken from 26 black and white women, matched for age and the stage of their cancer, who were either members of the US military, or were the dependant of a serving member. The researchers found 65 genes with significantly different levels of activity between tumours from the black and white patients. This time however there was no clear link with the immune system, and few of the genes discovered had previously been linked to cancer, so the cause of the differences is unclear. This is also to undergo further investigation. Field says the long-term goal is to identify new targets for drugs which could improve survival prospects for African Americans.

For further reference: Original article by Peter Aldhous, San Diego, NewScientist magazine.

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