Saturday, January 13, 2018

New test predicts age of onset of aggressive prostate cancer

CANCER DIGEST – Jan. 13, 2018 – A new test based on genomic research combined with population research is able to predict the age of onset of aggressive prostate cancer, researchers say.

The tool is based on searches of individual genomes, the entire set of genes that make up an individual, for small variations, called single-nucleotide polymorphisms or SNPs that occur more frequently in people with a particular disease compared to people without the disease.

An international team of researchers led by Tyler Seibert, MD, PhD, and Anders Dale, PhD, at the University of San Diego School of Medicine, with colleagues in Europe, Australia and the U.S. used these genomic-wide association studies (GWAS) to determine a man’s genetic predisposition to developing prostate cancer and predict his likelihood of developing a lethal form of the disease. They published their findings in the Jan. 11 journal BMJ (formerly the British Medical Journal).

Using a method of analysis developed at UC San Diego, called a polygenic hazard score, researchers are able to analyze hundreds of thousands of SNPs at the same time in large groups of people. In this study, the researchers looked at over 200,000 SNPs from 31,747 men of European ancestry participating in the ongoing international PRACTICAL consortium project.

The polygenic hazard score (PHS), involves survival analysis to estimate SNPs’ effects on age at diagnosis of aggressive prostate cancer. The results led to a PHS for prostate cancer that can estimate individual genetic risk. This score was then tested against an independent dataset, from the recent UK ProtecT trial, for validation.

“The polygenic hazard score was calculated from 54 SNPs and proved to be a highly significant predictor of age at diagnosis of aggressive prostate cancer,” said Seibert in a press release. “When men in the ProtecT dataset with a high polygenic hazard score were compared to those with average PHS, their risk of aggressive prostate cancer was at least 2.9 times greater.”

The study authors note that an individual’s genotype does not change with age, so the polygenic hazard score can be calculated at any time and used as a tool for men deciding whether and when to undergo screening for prostate cancer. Nevertheless they caution that further testing is needed before a PHS is ready for routine use.

No comments:

Post a Comment