Cancer diagnosis: pee instead of pecking?
Urine tests are one of the oldest methods of examining certain diseases such as the kidneys or urinary tract. Elimination can generally tell a lot about our state of health. Urine could also be useful for cancer diagnosis, as researchers now report.
The number of cancers is increasing
Health experts say that more and more people are getting cancer. Around half a million new cases are registered in Germany alone. The number of diagnoses in this country has almost doubled since 1970. However, patients can now hope for recovery better than before. However, an early diagnosis is important for this. According to researchers, urine could also be useful for cancer diagnosis.
Genetic material from urine
Researchers at Christian-Albrechts-Universität zu Kiel (CAU), the University Medical Center Schleswig-Holstein (UKSH) and the Lithuanian University of Health Sciences in Kaunas are convinced of the diagnostic potential of urine.
The reason for this is the genetic material it contains, which, as so-called cell-free DNA, offers new opportunities for cancer diagnosis, according to a statement from the University of Kiel.
According to the information, the researchers were able to extract as much genetic material from a quantity of 60 milliliters of urine - approximately half a urine beaker - in the laboratory as from a blood sample of ten milliliters.
The team of scientists worked on new methods to remove the cell-free DNA from the urine.
The researchers at the Institute for Clinical Molecular Biology (IKMB) at the CAU published their results together with their international colleagues in the journal "BioTechniques".
The amount of DNA in the urine varies greatly from person to person
As explained in the release, the term cell-free DNA refers to fragments of genetic information that are outside of cells in various body fluids.
These DNA components arise when body cells but also tumor cells die. They are first released into the bloodstream and from there, among other things, get into the urine.
The scientists initially encountered a number of problems: the amount of DNA in the urine varies greatly from person to person and varies greatly from day to day even with one and the same person.
For this reason, the DNA concentrations initially contained in the samples were sometimes too low, so that the researchers had to increase the amount of urine collected in each case.
They also regularly observed that the urine of healthy women contains more than twice the promising cell-free DNA for diagnosis than an identical amount in healthy men.
This fact must be taken into account in future cancer diagnosis so that these gender-specific differences do not falsify the results.
Cancer diagnosis tests usually work with blood samples
So far, tests for cancer diagnosis have mostly worked with blood samples. Some of these blood tests use cell-free DNA from a possible tumor to identify certain types of lung or colon cancer.
The experts would like to clarify in the next twelve months in the laboratory of the IKMB at Kiel University whether the genetic material from urine is as suitable for clinical research and diagnostics as blood, in further research.
"To do this, we will use the samples available from the study participants at the UKSH to compare the genetic traces of a tumor in blood plasma and urine and see whether the disease can be detected in both ways," says Michael Forster, scientist at the Institute for Clinical Molecular Biology at the CAU.
Advantages for patients
The researchers in Kiel hope to develop a urine-based procedure in the future that will allow diagnoses that are as reliable as conventional blood tests. Initially, this would offer advantages for patients who would be spared the unpleasant blood draw.
In addition, such a test procedure would be faster and less complex than the previous methods because, unlike blood tests, for example, no medical personnel is required for taking samples.
“Similar test methods for cancer diagnosis are already commercially available in the USA. Recently, an international research team also presented a newly developed, not yet clinically approved urine test for certain urinary tract tumors, ”Forster describes the current state of development.
And British researchers reported years ago about a urine test that can be used to diagnose pancreatic cancer.
"It will take a few years for clinical research and cost and benefit considerations to launch new urine-based clinical tests in Germany," said Forster. (ad)