Genetic screening of men at high risk for prostate cancer can identify those most at risk of aggressive disease.
Current diagnostic approaches for prostate cancer are not able to distinguish definitively between indolent disease, which may be present for many years without progression and does not require treatment, and aggressive disease – which progresses rapidly and needs prompt intervention.
New research funded by Prostate Cancer UK
and carried out at the Institute of Cancer Research used DNA sequencing to examine 22 known tumour suppressor genes
in nearly 200 men with apparent familial prostate cancer (prostate cancer patients with at least two affected relatives) and assess the relative risk conferred by mutations in these genes.
Many genetic variants have already been implicated in moderately increased prostate cancer risk, including mutations in genes also involved in the risk of other forms of cancer. Of the men in this study, over half also had at least one relative affected by breast, ovarian or colon cancer, as well as multiple relatives affected by prostate cancer.
In all, 7.3% of the men were found to have a harmful mutation in one of the 22 genes examined. The presence of one of these mutations was linked with an increased risk of more advanced disease (invasive, metastatic cancer). The researchers concluded that genetic testing could identify patients at increased risk of aggressive disease, for whom closer monitoring would be advisable.
Dr Iain Frame, Director of Research at Prostate Cancer UK, said that diagnosis of prostate cancer and treatment decisions were currently a ‘minefield’, adding: “We urgently need to understand more about which men are at risk of developing prostate cancer and in particular aggressive forms of the disease. Genetic testing to predict risk could revolutionise how we treat the 40,000 men diagnosed with the disease every year in the UK".
Comment: Although this was a small, proof-of-principle study, there are plans to extend it to a trial including 2,000 men and analysis of nearly 200 genes. Forms of genetic testing or screening among population sub-groups clearly have considerable potential to refine risk prediction and treatment or surveillance decisions, so planning for the impact of genetic risk stratification alongside ongoing research is important (see previous news).