Simple urine genetic test shows potential for early detection of bladder cancer

Screening for genetic mutations in urine can detect bladder cancer years before the disease shows clinical symptoms, new research suggests.

The study, conducted by researchers from France, Iran and the United States, identified mutations in ten genes that can predict the most common type of bladder cancer up to 12 years before diagnosis.

The results are being presented today at the Annual Congress of the European Association of Urology (EAU) in Milan.

Bladder cancer is not a rare disease – it is one of the ten most common cancers in the UK and fifth in the European Union, with over 200,000 cases in the E

U every year. Only about half of those diagnosed with advanced disease will survive beyond five years, primarily due to late diagnosis and disease recurrence. On the other hand, if their cancer is detected at an early stage, more than 80% of patients survive at least five years.

The diagnosis of bladder cancer relies on expensive and invasive procedures such as cystoscopy, which involves inserting a camera into the bladder. Having a simpler urine test that could accurately diagnose and even predict the likelihood of cancer years in advance could help catch more cancers early and avoid unnecessary cystoscopies in healthy patients.

Dr Florence Le Calvez-Kelm, Lead Researcher, International Agency for Research on Cancer (IARC) in Lyon

The study was based on the UroAmp test, a general urine test that identifies mutations in 60 genes, developed by Oregon Health Science University spin-off company Convergent Genomics. Building on previous research to identify genetic mutations linked to bladder cancer, the research team narrowed down the new test to focus on mutations in just ten genes.

Together with colleagues from Tehran University of Medical Sciences in Iran, they tested the potential new test using samples from the Golestan Cohort Study, which tracked the health of more than 50,000 participants over ten years. , all of whom provided urine samples at recruitment. Forty people in the study developed bladder cancer during that decade, and the team was able to test urine samples from twenty-nine of them, as well as samples from 98 other similar participants. as witnesses.

Of the 29 participants who had developed bladder cancer in the Golestan cohort, the test was able to accurately predict future bladder cancer in 19 (66%) of them, although samples from urine had been collected up to 12 years before clinical diagnosis. Fourteen of these participants were diagnosed with bladder cancer within seven years of urine collection, and the test was able to predict cancer in 12 (86%) of them. The test was exactly negative in 94 of the 98 participants (96%) who would not develop cancer in the future. Of those who tested negative but eventually developed bladder cancer, no cancer was diagnosed until at least six years after urine collection.

The test was also tested with colleagues at Massachusetts General Hospital and Ohio State University using samples from 70 bladder cancer patients and 96 controls, taken before a cystoscopy. Unlike the Golestan study, some of these samples were provided by cancer patients on the day they were diagnosed, rather than several years earlier.

Mutations were found in urine samples from 50 of 70 patients (71%) whose tumors were visible on cystoscopy. Some of these were new diagnoses and others involved cancer recurrence. Mutations were not found in 90 of 96 (94%) patients with a negative cystoscopy.

Dr. Le Calvez-Kelm believes that these results demonstrate the potential of a genetic urine test for the early detection of bladder cancer. She said: “We have clearly identified which are the most important acquired genetic mutations that can significantly increase the risk of developing cancer within ten years. Our results were consistent across two very different groups – those with known risk factors undergoing cystoscopy and people who were assumed to be healthy.

“If the results were to be replicated in larger cohorts, urine testing for these mutations could allow routine screening of high-risk groups, such as smokers or people exposed to known bladder carcinogens in the setting. of their work.

“This type of test could also be used when patients visit their doctor with blood in their urine, to help reduce unnecessary cystoscopies. If we can identify bladder cancer at an early stage, before the disease progresses , then we can save more lives.”

Dr Joost Boormans, member of the EAU Scientific Congress Bureau and urologist at Erasmus University Medical Center Rotterdam, said: “Research of this nature is very encouraging as it shows that our ability to identify molecular alterations in liquid biopsies such as urine which could indicate that the cancer is constantly improving.

“Although we need to develop more accurate diagnostics, it is unlikely that we will have a mass screening program for bladder cancer in the near future. Where a urine test for genetic mutations might show its value is in reducing cystoscopies and CT scans in bladder cancer patients who are being monitored for a recurrence, as well as those referred for blood in their urine A simple urine test would be much easier to undergo for patients than invasive procedures or scans, while being less expensive for health services.