Johns Hopkins Medicine and University of Southern California researchers have announced that a genetic marker tied to prostate cancer — previously seen in a significant number of Ugandan men with the disease — also could be found in larger populations of Black males with prostate cancer, including African Americans.

The finding was reported in the Sept. 2020 issue of the journal European Urology. The collaborative study was led by Christopher Haiman, Sc.D., professor of preventive medicine at the Keck School of Medicine of USC.

The biological marker that the researchers studied is a single variation in the DNA of chromosome 8 of the human genome. Known as a single nucleotide polymorphism (SNP), such variants can help scientists identify the connections between genes and specific diseases. Carrying the chromosome 8 SNP marker has been linked to a twofold increase in a man’s risk for prostate cancer, going to threefold or higher in men with a family history of the disease.

The research team examined the DNA of prostate cancer patients of African descent across the United States and found results similar to those observed in previous studies in Ugandan men. As this SNP is not found in Americans of European descent, the researchers say this finding may partly explain why African American men are significantly more likely to be diagnosed with prostate cancer and die from the disease.

This information opens an important door for future genetic testing. Study co-author William Isaacs, Ph.D., professor of urology and oncology at the Johns Hopkins University School of Medicine, says that a set of these SNP markers is being developed as a diagnostic tool for determining an individual’s prostate cancer risk level.

“We have to get these tests into the general practitioner’s office,” he says.

Having an SNP diagnostic test for prostate cancer, Isaacs explains, would enable clinicians to screen patients who they believe may be at highest risk for developing the disease, so they can be monitored for it and treated at an early stage if diagnosed.

Isaacs is available for interviews.