Prostate Cancer Genetic Test Can Provide Readout of Inherited Disease Risk

Prostate cancer genetics may be key to identifying those at high risk of developing the disease and guiding new treatments, according to a recent study of more than 140,000 men.

The study, led by researchers from The Institute of Cancer Research (ICR), has identified genetic variants in DNA code that indicate an increased risk of prostate cancer through a new DNA analysis test called Oncoarray.

Based on the findings, the combined effect of inheriting multiple genetic variations could have a substantial impact on the likelihood of developing prostate cancer. The test identified 1% of men who are at the highest risk because of having inherited many of these variants as being nearly 6 times more likely to develop the disease than the general population.

The test works by comparing more than a half-million single-letter changes in the DNA code of nearly 80,000 men with prostate cancer and more than 61,000 men without the disease to predict which men were most at risk of developing the disease in their lifetime.

Men who were at the highest risk were 5.7 times more likely than the population average to develop prostate cancer, corresponding to an absolute risk of 1 in 2. Additionally, the top 10% in the population risk distribution were 2.7 times more likely to develop the disease than the general population, which corresponds to a risk of almost 1 in 4.

“By looking at the DNA code of tens of thousands of men in more depth than ever before, we have uncovered vital new information about the genetic factors that can predispose someone to prostate cancer, and, crucially, we have shown that information from more than 150 genetic variants can now be combined to provide a readout of a man’s inherited risk or prostate cancer,” Rosalind Eeles, PhD, professor of oncogenetics at the ICR, said in a press release.

Additionally, many of the new genetic variants were found in the region of genes involved in communication between cells of the immune systems and other cells in the body, indicating that genetic errors in immune pathways may contribute to prostate cancer risk.

The researchers noted that they now believe enough is known about prostate cancer genetics to begin assessing whether testing can benefit patients.

According to the researchers, the new findings indicate an opportunity to now account for approximately 30% of a man’s inherited risk of prostate cancer. New information about the causes of the disease and the potential role of the immune system may be applied to the design of new treatments and practical testing strategies.

“We are on the cusp of moving from theory to practice — from explaining how genetics affects prostate cancer risk, to testing for genetic risk and attempting to prevent the disease,” Dr Eeles concluded in the press release.

References

Schumacher FR, Al Olama AA, Eeles RA, et al. Association analyses of more than 140,000 men identify 63 new prostate cancer susceptibility loci. Nature Genetics. 2018. https://www.nature.com/articles/s41588-018-0142-8.

Prostate cancer DNA test identifies men with six-fold increased risk [news release]. ICR’s website. https://www.icr.ac.uk/news-archive/prostate-cancer-dna-test-identifies-men-with-six-fold-increased-risk. Accessed June 12, 2018.