Calculating the genetic risk of men who visit primary care for suspected prostate cancer could lead to earlier diagnosis of the disease and avoid the need for invasive biopsies, U.K. research suggests.
With the U.K. primary care physicians making around 800,000 prostate cancer referrals in the U.K. each year, incorporating genetic risk would fast-track 160,000 men for investigation.
A further 320,000 men could be identified as at low risk of prostate cancer and avoid the need for referral and biopsies.
“This is potentially an exciting new strategy for early cancer detection,” said lead investigator Sarah Bailey, a senior research fellow at the University of Exeter Medical School in the U.K.
“Not only can high risk patients be fast tracked, but those at low risk can safely avoid invasive investigations.“
She added: ”Using this technique would align well to the NHS Long Term Plan, which pledges to become the first national health care system to offer whole genome sequencing as part of routine care.”
Prostate cancer is responsible for approximately a quarter of all new cancer cases in men, with 52,000 new diagnoses each year in the U.K. alone and rates rising by 4 per cent each year.
Although it is the second most common cause of cancer death for men in the U.K., five-year survival doubles if it is identified at an early versus late stage.
Currently, the prostate specific antigen (PSA) test is used for men with new-onset erectile dysfunction or lower urinary tract symptoms, such as needing to wake up at night to urinate or a weak urine stream.
Although it is the only test currently available for detecting prostate cancer in UK primary care, false positives are common and only a third of those testing positive actually has the cancer.
It also misses approximately 15 percent of cases.
Using 269 known genetic variants for prostate cancer, the researchers attempted to improve on the current situation by creating a genetic risk score for the disease.
They then applied this to 6930 White European men on the UK Biobank who had consulted a primary care practitioner for lower urinary tract symptoms.
After excluding those with pre-existing cancer or who died within a two-year period, the team compared 6468 control individuals without prostate cancer with 247 who developed this cancer within two years.
The researchers report that the genetic risk score was associated with prostate cancer in symptomatic men, with an odds ratio of 2.12 per standard deviation increase.
An integrated risk model including age and genetic risk score applied to symptomatic men predicted prostate cancer. The incidence of prostate cancer was 8.1% in the highest risk quintile versus less than one per cent in the lowest quintile.
Lead author Harry Green, an independent research fellow also at the University of Exeter Medical School, said: “Our study is the first to demonstrate that incorporating genetic risk into GP’s risk assessment of patients’ symptoms of possible prostate cancer could result in faster referral for those at most risk.”
The research is published in the British Journal of Cancer.
