SYDNEY, Sept. 1 (Xinhua) -- Australian scientists in an international research team have identified "genetic signatures" that they believe can help explain why men from some ethnic backgrounds are more prone to suffer from severe forms of prostate cancer.
Their findings, published simultaneously on Thursday in two journals, Nature and Genome Medicine, showed that men of African descent have more than double the chance of succumbing to that cancer than men of other racial heritages.
"Our understanding of prostate cancer has been severely limited by a research focus on Western populations," said University of Sydney (USYD) genomicist Vanessa Hayes in an online article in Scimex on Thursday.
While genomics holds a critical key to unraveling contributing genetic and non-genetic factors, data for Africa has until now been lacking, Hayes said.
The researchers, who included scientists from South Africa, Brazil and Britain, used a process called whole-genome sequencing to map the genetic code of cancer cells.
"A strength of this study was the ability to generate and process all data through a single technical and analytical pipeline," Hayes said.
From that study of 183 untreated forms of prostate tumors from men in Australia, Brazil and South Africa, they identified more than 2 million cancer-specific genomic variants.
"We found Africans to be impacted by a greater number and spectrum of acquired genetic alterations, with significant implications for ancestral consideration when managing and treating prostate cancer," Hayes said.
USYD computational biologist Weerachai Jaratlerdsiri said the study revealed a "novel prostate cancer taxonomy which we then linked to different disease outcomes."
As part of her doctoral work at USYD, Tingting Gong sifted through the genomic data for large changes in the structure of chromosomes.
"We showed significant differences in the acquisition of complex genomic variation in African and European derived tumors," Gong said.
The researchers said these important changes were often overlooked because of the complexity involved in computationally predicting their presence.
Hayes said the research was a legacy of South Africa's Archbishop Emeritus Desmond Tutu, who had his complete genome sequenced.
Tutu, who died of that cancer last year, was "an advocate for prostate cancer research in southern Africa... and the benefits that genomic medicine would offer all peoples," said Hayes. "We hope this study is a first step to that realization."
Hayes told Xinhua that the researchers would next work on seeing what role environmental factors might play in triggering cancer.
"There remains a lot that needs to be understood," she said. ■