University of Pennsylvania Cancer Center
Last Modified: May 18, 1999
Researchers at New York Presbyterian Hospital have devised the first kidney cancer blood test that may spare some patients removal of their kidneys. Although not yet accurate enough to be used as a screening tool for the general population, the test did detect 60 percent of cancers in a test group of kidney cancer patients. It did not detect any cancer in subjects that did not have kidney cancer.
The experimental assay looks for two kidney cancer markers in a single sample of blood: proteins produced by the gene MN/CA9, found in clear cell carcinoma of the kidney and prostate specific membrane antigen (PSMA), which can also be expressed in kidney cancer. Led by Dr. James McKiernan, the researchers used the test on 40 patients known to have kidney cancer and 20 "control" subjects that were cancer-free.
McKiernan reports that the test can best be used to help diagnose cancer in patients who are discovered to have a mass in their kidneys. Because early kidney cancer remains relatively symptom-free, a growing mass in the abdomen is usually only detected during radiological exams ordered for another purpose, such as a gastrointestinal complaint. Once the mass is detected, the affected kidney is usually removed -- both because it is not feasible to take a biopsy of kidney tissue, and because no tests exist to rule out cancer in the organ. McKiernan says this test could help diagnose such kidney masses and could be used to monitor patients who have already had their cancerous kidneys removed to see if their cancer has returned.