Researchers Create Highly Accurate Test for Bladder Cancer
Bladder Cancer Test
Bladder cancer is often difficult to diagnose. Diagnostic tests have been created based on the increasing knowledge of molecular changes that occur as this cancer (also called urothelial cancer) progresses. Until now, none of the tests had the optimal sensitivity and specificity to detect the cancer.
Dr. Dan Theodorescu and his team from the UVa Paul Mellon Prostate Cancer Institute and the University of Virginia Health System and colleagues in industry have created a test that correctly identified all samples of known cancer and all samples from healthy subjects in a clinical study. The test was found to be very specific (correctly sorting cancer from noncancer samples) and sensitive (finding all cancer samples out of all of the samples tested). The test can be used on a sample of urine provided by the patient.
The research team used mass spectrometry and capillary electrophoresis, laboratory methods that help to separate, measure and analyze the molecules of a substance, to compile a precise pattern of 22 polypeptide masses. Polypeptides are chains of amino acids, which are the building blocks of proteins. In one portion of the study, this diagnostic pattern correctly identified all 31 samples of urothelial cancer and also all 11 samples of tissue from the urine of healthy patients.
These established polypeptide patterns might improve the sensitivity and specificity when diagnosing urological disease and cancer in particular. "We are working hard to get this technology or a variation of it in the clinical labs, where we will not only diagnose cancer noninvasively, but we also will determine how the cancer will behave and how best to treat it. Basically, we are aiming for the goals of personalized medicine," said Dr. Theodorescu.
The study also included a group of samples from patients with other types of cancer and those with nonmalignant genitourinary disease, such as inflammatory disease of the urinary tract. The diagnostic test was able to correctly identify the samples from patients with other malignant and nonmalignant disease from those with bladder cancer 86 to 100 percent of the time. This was an important breakthrough as previous urinary tests have not been able to accomplish this with similar specificity.
Overall, this study identified and validated three patterns of polypeptides found in urine from a group of healthy individuals, patients with bladder cancer, and individuals with genitourinary disease or non-bladder cancer. The three patterns are: a pattern for bladder cancer, a pattern for nonmalignant diseases and a pattern for cancers that are not bladder cancer. This test using polypeptide patterns is valuable because of its high-level accuracy in a field of medicine in which so many other diseases can routinely be diagnosed when assessing patients for urological disease.
This study is featured on the Lancet website at http://www.thelancet.com