Gene May Explain Higher Rates of Some Cancers in Black People

Tests were done on mice, but need to be confirmed in humans, researchers say

By Robert Preidt

Thursday, March 31, 2016

THURSDAY, March 31, 2016 (HealthDay News) -- A single gene variant may explain why black Americans with common cancers have shorter survival times and higher death rates than other races, a new study suggests.

While some researchers have examined possible socioeconomic factors to explain these differences, others have focused on genetics.

"We may finally have a truly genetic explanation for why African-Americans are more prone to a variety of cancers," said study senior author Maureen Murphy. She is a professor and program leader in the Molecular and Cellular Oncogenesis program at the Wistar Institute in Philadelphia.

"This is a variant that has never been observed in Caucasian populations, so identifying people who have this variant may be crucial for providing improved prognosis and personalized treatment that will lead to better outcomes," she said in an institute news release.

In this study, researchers zeroed in on a specific variant in a tumor suppressor gene that is mutated and activated in most cancers. This variant occurs only in people of African descent. It's present in about 2 percent of African-Americans and up to 8 percent of Africans, the study authors said.

The researchers then created a mouse model to study the effects of this particular variant. In mice, 80 percent of those with the variant developed cancer. The most common types of cancers in mice with the variant were liver cancer, colon cancer and lymphoma, the study found.

It's important to note that findings in mice don't always translate to humans.

However, liver cancer is more common in African-Americans than in other racial/ethnic groups, the researchers said. And colon cancer accounts for about 9 percent of all newly diagnosed cancer cases among African-Americans, the researchers noted.

The study's findings need to be validated in humans, Murphy said. To do that, researchers said they would need a large population of people to see this gene variant's effects.

"However, we now have some of the strongest evidence ever obtained for a genetic basis for this disparity and a larger, population-based study is warranted," Murphy said.

Results of the study were published in the journal Genes and Development.

SOURCE: Wistar Institute, news release, March 30, 2016

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