The study reveals this is because of their elevated levels of prostate-specific antigen in the blood. The protein, known as PSA, is produced by both normal and malignant cells in the prostate gland and can signify prostate cancer risk.
Prof Riana Bornman, Senior Research Professor at the University of Pretoria’s School of Health Systems and Public Health (SHSPH), and Prof Vanessa Hayes, a genomicist from the Garvan Medical Institute for Medical Research in Sydney, Australia, focused their research on prostate cancer in black Southern African men of Bantu and Khoisan descent, to better understand the possible links between prostate cancer and African ancestry.
Their study covered hospitals in Limpopo and Gauteng, where 99% of the participants were self-identified black African patients who had a more aggressive prostate cancer compared with similar studies conducted on European patients.
Previous research has shown that African-American men are 1,7 times more likely to develop prostate cancer and are generally younger, in their 40s and 50s at diagnosis as compared with European Americans.
They also present with more aggressive disease characteristics and consequently are also 2,5 times more likely of dying from the disease.
This current study included 837 men between 45 and 101, with a mean age of 70 years, who all had prostate disease. Of this group, 522 patients (62,4%) had prostate cancer. Black South African men presented with higher PSA levels and histopathological tumour grade compared with black Americans.
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This difference was further exacerbated in men from rural localities. “The most common risk factors for prostate cancer include African ancestry, increasing age, from 50’s onwards, and a family history of prostate cancer – on either the maternal or paternal side,” said Bornman.
The research authors said it might be that prostate cancer grows more rapidly in black than in white men and that transformation from latent to aggressive prostate cancer might occur earlier in black men.
“Because African ancestry is a risk factor, it means that for scientists to understand what leads to the development of prostate cancer, we have to investigate prostate cancer in African men – this means that African ancestry and aging will both be covered as risk factors,” she added.