Researchers have identified genetic risk factors that may contribute to prostate cancer in a diverse group of African men, according to a recent study published by Janivara et al in Nature Genetics. The findings could uncover new treatment options in this patient population.
Background
Certain prostate cancer variations are not found in European populations, which contribute to higher disease rates in unscreened African groups because European data has thus far guided interventions in Africa.
“From the literature, men of African descent have a much higher risk of developing prostate cancer during their lifetime. It tends to develop at an earlier age and is more aggressive, [b]ut we have only really studied prostate cancer in European populations. By studying genetic risk factors in men [of African descent]—at a large scale—we can one day refine screening and treatment,” highlighted co–study author Carl Chen, BScHons, PhD, MSc(Med)(BME), a researcher at the Sydney Brenner Institute for Molecular Biosciences at Wits University.
Study Methods and Results
In the recent study, the researchers enrolled nearly 8,000 African men—50% of whom had prostate cancer and 50% of whom didn’t have the disease—from five African countries across West, East, and Southern Africa.
“We identified three loci, or genetic regions, strongly associated with increased prostate incidence. The top signals within these three loci are unique to African populations and would not have been found if we didn’t study African populations,” Dr. Chen said. Notably, the researchers revealed that regional differences in the strength of the signals between East, West, and Southern Africa may exist—representing different types of risks across Africa.
To address the need for unique genetic diversity in African populations, the Sydney Brenner Institute for Molecular Biosciences Biobank processed approximately 2,000 biosamples—nearly 25% of the total study sample. Currently, the Biobank holds about 30,000 DNA samples from participants of African descent, gathered from numerous research projects.
“The research infrastructure is crucial for supporting large-scale genetic research in Africa," emphasized co–study author Natalie Smyth, PhD, Manager of the Sydney Brenner Institute for Molecular Biosciences Biobank and Laboratory.
The researchers noted that unique genetic variations could help explain why current prostate cancer screening methods may be less effective among African men.
Conclusions
The researchers hope their findings can help illuminate the molecular risk factors of common cancer types in Africa.
“The findings from this study will lay the foundation to develop models for risk prediction using genetic data to improve the treatment of prostate cancer. Prostate cancer screening is virtually nonexistent in Africa, allowing for the study of the natural history and genetic associations of prostate cancer in the absence of early detection,” indicated Michèle Ramsay, BSc(Agric), MSc, PhD, Director of the Sydney Brenner Institute for Molecular Biosciences at Wits University. “We aim to uncover region-specific genetic mutations and variations, leading to more accurate, culturally relevant treatments that address the unique genetic diversity of African populations, ultimately improving cancer care and outcomes across the continent," she added.
The research demonstrated the importance of genetic research in diverse populations. Future studies should use ancestry-specific data to address differences in genomic medicine.
The researchers stated that the recent study is a product of the Men of African Descent and Carcinoma of the Prostate (MADCaP) network, which includes African and U.S. investigators who have explored prostate cancer causes, risks, screening, and clinical management over the past 20 years.
“MADCaP is guided by the development of world-class research that affects African populations. Biosampling, genotyping, and data management are performed in Africa to build local capacity for cancer research,” underscored senior study author Timothy Rebbeck, PhD, of Dana-Farber Cancer Institute and Harvard University. "The MADCaP network ensures that data from different centers, including both risk factors and clinical data, are consistent. They hold meetings to encourage communication between clinicians and bioinformaticians. The MADCaP network has also developed a new genotyping array specifically designed to identify genetic links to cancer in African populations, in addition to enhancing research capabilities,” he continued.
The researchers concluded that their findings reveal that prostate cancer is a complex disease and that exploring this type of cancer in diverse populations with a high disease burden could be critical because they may possess genetic risk variants absent in other patient populations.
Disclosure: For full disclosures of the study authors, visit nature.com.
