Washington (US): A comprehensive tool for predicting an individual’s developmental risk Prostate cancer Created by Cambridge scientists. They say this could help ensure that people at highest risk get the right test while reducing unnecessary — and potentially invasive — testing for people at very low risk.
can risk-prostate, developed by researchers at the University of Cambridge and The Institute of Cancer Research, London, will be incorporated into the group’s CanRisk web tool, which has now recorded nearly 1.2 million risk predictions. The free tool is already being used by Healthcare professionals worldwide to help predict the risk of developing breast and ovarian cancer.
Prostate cancer is the most common type of cancer in men. According to Cancer Research UK, more than 52,000 men are diagnosed with the disease each year and more than 12,000 die. Three-quarters (78 per cent) of men diagnosed with prostate cancer survive for more than ten years, but this proportion has barely changed over the past decade in the UK.
Testing for prostate cancer involves a blood test that looks for a protein called a Prostate-specific antigen (PSA) which is produced only by the prostate gland; However, it is not always certain. According to the NHS website, three out of four men with elevated PSA levels do not have cancer. Further tests, such as a tissue biopsy or MRI scan, are therefore required to confirm the diagnosis.
Professor Antonis Antoniou, from the University of Cambridge’s Department of Public Health and Primary Care, said: “Prostate cancer is the most common cancer in men in the UK, but population-wide screening based on PSA is not an option: these tests are often false positive, which That means many men will then be biopsied unnecessarily. Also, many prostate tumors identified by PSA tests are slow-growing and not life-threatening. Treating these tumors can do more harm than good.
“What we need is a way to identify men who are most at risk, allowing screening and diagnostic tests to be targeted where they are most needed, while also reducing harm to men who are at low risk of the disease. This is what CanRisk-Prostate aims to do. For the first time, it combines information on genetic makeup and prostate cancer family history, which are major risk factors for the disease, to provide individual cancer risks.”
Prostate cancer is the most genetically determined of the common cancers. Inherited defective versions of the BRCA2, HOXB13, and possibly BRCA1 genes are associated with moderate-to-high risk of prostate cancer, although such defects are rare in the population. In addition, there are several more common genetic variants that each confer a low risk, but overall they act like ‘volume controls’ that moderate or increase the risk of prostate cancer.
Writing in the Journal of Clinical Oncology, the researchers – supported by Cancer Research UK – describe the development of the first comprehensive prostate cancer model using genetic and cancer family history data from nearly 17,000 families affected by prostate cancer. It uses a risk score based on rare genetic defects in moderate-to-high-risk genes and 268 common low-risk variants, including a detailed cancer family history, to predict future risks.
One in six men (16 percent) will develop prostate cancer by age 85. Using the model, the team found that the predicted risk was higher for men whose fathers were diagnosed with prostate cancer — 27 percent if the father was diagnosed at an older age (80 years), but as high as 42 percent if the father was diagnosed. Diagnosed at a young age (50 years).
The risks were significantly higher for men with the genetic defect. For example, 54 percent of men who carry BRCA2 gene mutations develop prostate cancer—however, among men with BRCA2 gene defects, the risks were significantly lower if they also had the low-risk variant, but not if they had the low-risk variant. A lot more if the types are also large in number.
In practice, the researchers say, clinicians will be able to use any combination of family history of cancer, rare and common genetic variants to assign individual risk.
To validate their model, the team ran the risk model on an independent cohort of more than 170,000 men recruited to the UK Biobank, a biomedical database and research resource containing anonymised genetic, lifestyle and health information from half a million UK participants. All of these men were free of prostate cancer when they were recruited for the study, but over the next ten years, more than 7,600 developed prostate cancer.
In validating their model, the researchers found that 86 percent of UK Biobank participants who developed cancer were in the half of men with the highest predicted risk, suggesting that targeting screening and diagnostic tests is feasible. The population at highest risk, most of whom will develop cancer.
Dr from the MRC Biostatistics Unit at Cambridge. Tommy Nyberg said: “We have created the most comprehensive tool ever to predict a man’s risk of developing prostate cancer. We hope this will help clinicians and genetic counselors assess their clients’ risk. Appropriate follow-up.”
“Over the next 12 months, we aim to build this tool into the widely used CanRisk tool, which will facilitate risk-based clinical management of men seen in family cancer clinics and enable a risk-adapted early detection approach for the population at large.”
Professor Ross Iles of The Institute of Cancer Research, London, and co-author of the study, said: “This is an important step because it will be able to communicate with doctors about the individual risk of prostate cancer with men in the most accurate computer-based model to date. This will allow them to screen. will help in making decisions about.”
Until now, the data used to develop CanRisk-Prostate has been from men of European descent. The team hopes to be able to include data from men of other ethnicities as more research is conducted.
