Studying patients with kidney cancer, a team of researchers at Washington University School of Medicine in St. Louis has identified a pair of proteins excreted in the urine that could lead to earlier and more accurate diagnosis of the disease.
The research, published online in the May issue of Mayo Clinic Proceedings, is the first to identify proteins secreted in urine that appear to accurately reveal the presence of about 90 percent of all kidney cancers.
Currently, there is no diagnostic test for kidney cancer. About 80 percent of kidney tumors are discovered incidentally, during a CT scan or ultrasound test that has been ordered for an unrelated abdominal complaint.
"Kidney cancer is a silent and frequently fatal cancer," says principal investigator Evan D. Kharasch, MD, PhD. "More than 80 percent of patients die within two years of diagnosis, and more than 95 percent die within five years because by the time the cancer is detected, it often has spread beyond the kidney. When it is identified early, however, kidney cancer is curable in a very high percentage of individuals."
Kharasch and co-investigator Jeremiah J. Morrissey, PhD, looked at urine samples from 42 patients who became aware that they had kidney cancer during an abdominal imaging test and from 15 individuals who did not have cancer but were scheduled for surgery. Another 19 healthy volunteers were included who were not having surgery of any kind.
The researchers focused on two proteins that previously had been found in kidney tumors: aquaporin-1 (AQP1) and adipophilin (ADFP). They discovered large amounts of those proteins in urine samples from kidney cancer patients.
The AQP1 or ADFP proteins were not elevated in healthy individuals or surgery patients without cancer. The researchers also found that when the kidney tumors were removed, AQP1 and ADFP levels in the urine declined precipitously.
"We believe that in the same
|Contact: Jim Dryden|
Washington University School of Medicine