New research shows that testing urine for genetic mutations can find bladder cancer years before it causes symptoms.
Researchers from France, Iran, and the United States have conducted a study which has identified mutations in ten genes. These mutations can predict the occurrence of the most common type of bladder cancer up to 12 years before its diagnosis.
The research was presented at the annual meeting of the European Association of Urology (EAU) in Milan today.
Bladder cancer affects approximately 57,000 men and 18,000 women every year in the United States, leading to the deaths of approximately 12,000 men and 4,700 women annually.
Bladder cancer is one of the top 10 malignancies in the UK and the fifth most frequent in the EU, with over 200,000 cases each year. Due mostly to late detection and recurrence, only around half of people diagnosed with the advanced illness will live more than five years. If their cancer is found early, on the other hand, more than 80% of patients will live at least five years.
“Diagnosis of bladder cancer relies on expensive and invasive procedures such as cystoscopy, which involves inserting a camera into the bladder,” points out lead author Dr. Florence Le Calvez-Kelm.
“Having a simpler urine test that could accurately diagnose and even predict the likelihood of cancer years in advance,” according to the lead author, “could help to spot more cancers at an early stage and avoid unnecessary cystoscopies in healthy patients.”
The research relied on the UroAmp test created by Convergent Genomics, a spin-off of Oregon Health & Science University that can detect mutations in 60 genes with a single urine sample. The new test was developed by drawing on prior studies that had shown abnormalities in only 10 genes to be associated with bladder cancer.
They used samples from the Golestan Cohort Study, which has monitored the health of more than 50,000 participants over the course of ten years. All of the participants in the study provided urine samples when they were recruited, and the researchers from Iran’s Tehran University of Medical Sciences worked with them to test the potential new test using samples from the study. Researchers were able to analyze urine samples from 29 of the 40 study participants diagnosed with bladder cancer during that decade, in addition to samples from 98 control individuals with comparable characteristics.
The test was able to reliably predict future bladder cancer in 19 (66%) of the 29 patients who had bladder cancer within the Golestan cohort, even when urine samples were obtained as long as 12 years prior to clinical diagnosis. Results showed that the test correctly predicted bladder cancer in 12 (86%) of the 14 people who were diagnosed with the disease within seven years of the first urine sample. 94 out of the 98 subjects (96%) who did not go on to develop cancer had an accurate negative test result. No cancer was discovered until at least six years following the urine collection in those cases when the test came out negative but who ultimately did have bladder cancer.
In addition, the test was evaluated in collaboration with researchers from Massachusetts General Hospital and Ohio State University utilizing samples obtained from 70 patients diagnosed with bladder cancer and 96 healthy controls prior to the performance of a cystoscopy. In contrast to the findings of the Golestan research, some of these samples were collected from cancer patients on the same day that they received their diagnoses, as opposed to several years earlier.
In the urine samples of 50 of the 70 patients (71%) whose tumors could be seen during the cystoscopy, mutations were found. They included new and recurrent cancers. In 90 of the 96 (94%) individuals with a negative cystoscopy, no mutations were discovered.
These findings, in the opinion of Dr. Le Calvez-Kelm, show the promise of a genetic urine test for the early diagnosis of bladder cancer.
“We’ve clearly identified which are the most important acquired genetic mutations that can significantly increase the risk of cancer developing within ten years. Our results were consistent across two very different groups – those with known risk factors undergoing cystoscopy and individuals who were assumed to be healthy.
If the findings are confirmed in larger groups, screening high-risk populations like smokers or individuals exposed to bladder carcinogens at work through urine tests for these mutations could become a routine practice.
Such testing could also be helpful in reducing the number of unnecessary cystoscopies when patients report hematuria (blood in urine) to their doctors. Early detection of bladder cancer, before it advances, could lead to more lives being saved.
According to Dr. Joost Boormans, a urologist at the Erasmus University Medical Center Rotterdam and member of the EAU Scientific Congress Office, this research is encouraging because it demonstrates our improving ability to detect molecular changes in liquid biopsies, such as urine, that may indicate cancer.
“While we do need to develop more accurate diagnostics, it’s unlikely that we’ll have a mass screening programme for bladder cancer in the near future.
However, a urine test for genetic mutations could prove valuable in reducing cystoscopies and scans in patients with bladder cancer who are being monitored for recurrence, as well as those who exhibit hematuria.
“A simple urine test would be far easier for patients to undergo than invasive procedures or scans, as well as being less costly for health services.”
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