Bladder cancer: towards a urine test to predict it years in advance?

Bladder cancer towards a urine test to predict it years

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    Michaël Peyromaure (urologist)

    New international research indicates that screening for genetic mutations in urine may be able to detect bladder cancer years before the first symptoms appear. The opinion of Professor Michael Peyromaure, head of the urology department at Cochin hospital on this progress.

    Bladder cancer is by no means a rare disease, it is even the fifth most common cancer in the European Union, with more than 200,000 cases discovered each year. It is also known for its dire prognosis: only half of people diagnosed with advanced disease will survive more than five years, mainly due to late diagnosis and disease recurrence. A fatality that would fail if detected at an early stage.

    But a study by researchers from France, Iran and the United States has identified mutations in 10 genes that can predict the most common type of bladder cancer up to 12 years before diagnosis. This discovery is reflected in a simple urine test. The results were presented on March 10 at the Annual Congress of the European Association of Urology (EAU) in Milan.

    Mutations visible in two joint studies

    The study was based on testing UroAmp, a general urine test that identifies mutations in 60 genes, developed by Convergent Genomics. Building on previous research, the research team narrowed down the new test to focus on mutations in just ten genes linked to bladder cancer.

    This new test has potential, was used on samples from the Golestan (Iran) cohort study, which followed 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. Here is what comes out of it:

    • 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 at Massachusetts General Hospital, 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 disease-free patients (94%) with a negative cystoscopy.

    Extend the studies and quantify the cost of this test

    If the proposed urine test is not infallible in the discovery of bladder cancer, it is not devoid of potential and presents a non-invasive option and an interesting new tool.

    “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 detect more cancers early and avoid unnecessary cystoscopies in healthy patients.” enthuses the lead researcher, Dr Florence Le Calvez-Kelm, from the International Agency for Research on Cancer (IARC) in Lyon.

    If the results are going to need 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 the urine, to reduce unnecessary cystoscopies. If we can identify bladder cancer at an early stage, before the disease progresses, then we can save more lives.” she continues.

    Real progress for Professor Michael Peyromaure, head of the urology department at Cochin Hospital in Paris, contacted by Doctissimo, who recalls that its generalization can only be done if the test has an affordable price:

    “Very many studies have already attempted to identify a urinary marker to detect bladder tumors (first diagnosis or recurrence), which would make it possible to avoid the need for endoscopic examinations. Although imperfect, this one seems to have promising results. However, there is a lack of data on a larger scale, and it is also necessary to specify the cost of this new tool. Indeed, for its distribution to be done routinely, its cost would have to be acceptable compared to fibroscopy or a simple ultrasound.