PCR Test Can Diagnose Kidney Cancer in Urine

A methylation-specific polymerase chain reaction (CPR) test has shown the ability to identify kidney cancer, including stage 1 cancer, in the urine of patients. Following removal of the cancerous kidney, the test showed no DNA evidence of disease. The findings were presented at the annual meeting of the American Urological Association in San Francisco (CA, USA) in May 2004.

The prognosis for advanced kidney cancer is poor, whereas the early diagnosis of kidney cancer can result in curative treatment. The challenge has been to develop an inexpensive, noninvasive, accurate, and simple screening test. The new urine test meets these criteria. Moreover, when the test was used on urine from control subjects, people without cancer, it showed none of the gene alterations found in the urine of people with cancer.

"We used a common laboratory procedure to test the urine of 50 patients with kidney cancer,” explained Paul Cairns, Ph.D., a molecular biologist at Fox Chase Cancer Center (Philadelphia, PA, USA; www.fccc.edu). "Forty-four of the 50 tests showed gene changes in the urine that were identical to the gene changes found in the tumor tissue taken at the time of surgery.”

The new test searches for six cancer specific tumor-suppressor genes that were altered, causing them to fail in their role of preventing errant cell growth. These six genes are usually identified only after a pathologist's review of tumor tissue. Currently, kidney cancer is diagnosed after radiographic imaging by ultrasound, a computed tomography (CT) scan and/or a magnetic resonance imaging (MRI) scan. A biopsy of a kidney mass can be difficult to interpret or may give a false negative result. There is no protein marker test for kidney cancer as there is for prostate cancer.

"The test appears to be remarkably accurate, with no false-positives in this study,” said lead author Robert G. Uzzo, M.D., a urologic surgeon at Fox Chase Cancer Center. "In addition, one of the most impressive outcomes of this research is that the test also identified 27 of the 30 patients with stage 1 disease.”




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Fox Chase Cancer Center