Two groundbreaking studies published simultaneously in Nature and Genome Medicine today have identified genetic traits that explain ethnic differences in the severity of prostate cancer, especially in sub-Saharan Africa.
By performing genetic sequencing of prostate cancer tumors from Australian, Brazilian and South African donors, a team of researchers has identified a new taxonomy (classification scheme) for prostate cancer and cancer factors that not only distinguish patients by genetic origin, but also predict which cancers can become life-threatening which is currently a difficult task.
“Our understanding of prostate cancer has been severely limited due to the focus of research on Western populations,” says senior author Professor Vanessa Hayes, genomist and chair of the Petre Chair of Prostate Cancer Research at the University of Sydney’s Charles Perkins Center and Faculty of Medicine. and healthcare in Australia.
Being of African descent or African descent more than doubles the risk of developing fatal prostate cancer. “While genomics is a critical clue to genetic and non-genetic factors, data from Africa have not yet been available.”
“Prostate cancer is a ‘silent killer’ in our region. “We had to start from a grassroots approach, engaging communities in open discussion, building the infrastructure to include Africans in the genomic revolution, and at the same time identifying the true extent of prostate disease,” said the professor at the University of Pretoria. Riana Bornman is an international expert in men’s health and clinical director of the South African Prostate Cancer Study in South Africa.
Using sophisticated whole genome sequencing (a method of mapping the entire genetic code of cancer cells), more than two million cancer-specific genomic variants were identified in 183 untreated prostate tumors in men living in the three study areas.
“We found that Africans are subject to a greater number and range of acquired (including cancer drivers) genetic changes, which has significant implications for ancestry considerations in prostate cancer treatment,” said Professor Hayes.
“Using cutting-edge computational data science, which has allowed patterns to be recognized that include all types of cancers, we have identified a new taxonomy of prostate cancer, which is then linked to different disease outcomes,” said Dr. Virachai Jaratlerdsiri, a computational biologist at the University of Sydney and first author of the paper. in Nature.
“Combining our unique data set with the largest public source of data on cancer genomes in Europe and China allows us to present for the first time the genomic landscape of prostate cancer in Africa in a global context.”
As part of her doctoral dissertation at the University of Sydney, Dr. Tingting Gong, the first author of a paper in Genome Medicine, painstakingly sifted through genomic data looking for large changes in the structure of chromosomes (molecules that store genetic information). These changes often go unnoticed due to the difficulty of computationally predicting their presence, but they are of great importance for the development of prostate cancer.
“We have shown significant differences in the acquisition of complex genomic variations in tumors derived from Africans and Europeans, which has implications for disease progression and new treatment options,” said Dr. Gong.
This cancer genome resource is perhaps the first and largest in the world to include data on Africans.
“By including African data, we have taken the first steps not only towards the globalization of precision medicine, but also towards reducing prostate cancer deaths in rural Africa,” explains Professor Bornman.
The study, presented in the journals Nature and Genome Medicine, is part of the legacy of the late Archbishop Desmond Tutu. He was the first African to have a fully sequenced genome, whose data has become an integral part of genetic sequencing and prostate cancer research in South Africa. The sequencing results were published in the journal Nature in 2010.