Researchers at the Stanford University School of Medicine in the US have developed a highly sensitive urine test to diagnose and monitor bladder cancer.
Stanford University associate professor of radiation oncology Dr Maximilian Diehn was one of the researchers who created the bladder cancer urine test. He said: “This study describes a new diagnostic approach to bladder cancer focused on analysis of urine samples. Urine is in direct contact with bladder tumors, which shed some of their DNA into it.”
The test relies on this tumour shedding as it can pick up fragments of the cancer DNA and use this to highlight a positive result for bladder cancer.
The research was published online in Cancer Discovery. Diehn shares senior authorship with associate professor of medicine Dr Ash Alizadeh. Postdoctoral scholars Dr Jonathan Dudley and Dr Joseph Schroers-Martin are the lead authors.
The current process for testing for bladder cancer involves multiple steps as the symptoms can be similar to a number of other conditions.
More than 80,000 people in the US are diagnosed with bladder cancer each year. Currently, the most accurate diagnosis method for the disease is cystoscopy, an invasive method which takes tissue samples from the bladder.
The Stanford University researchers built upon earlier studies co-authored by Diehn and Alizedah, which showed that certain cancers could be detected by looking for DNA fragments of tumours in the bloodstream. They did this by using a method called cancer personalised profiling by deep sequencing (CAPP-Seq).
In the new study, the researchers modified molecular and bioinformatics aspects of the CAPP-Seq technique so it could be applied to bladder cancer DNA fragments found in urine.
A total of 67 healthy adults and 118 patients with early-stage bladder cancer were analysed. All study participants had urine collected prior to treatment or during surveillance.
The researchers discovered that testing for bladder cancer in urine highlighted cancer in its early stages of development, when it can be treated more easily.
The new bladder cancer urine test was able to identify the presence of bladder cancer in 83% of patients with early-stage bladder cancer, compared with only 14% for the clinically available urine cytology test.
The researchers said that their test has the benefit of being able to detect the recurrence of bladder cancer after someone has been treated for the disease.
Alizadeh said: “In our test samples, we were able to detect bladder cancer recurrence an average of 2.7 months earlier than could be done with cystoscopy.”
During the study, the test enabled the researchers to detect almost all cases of recurrent bladder cancer and was said to have nearly double the sensitivity of cystoscopy and cytology.
The researchers think that looking for cancer DNA in body fluids other than blood could be applied for many other cancers.
Diehn added: “It may eventually be useful for testing saliva for oral cancer, cerebrospinal fluid for neurological cancers or sputum for lung cancer.”