An immunoassay that tests for the presence of three biomarkers proved to be a valid screening method for early detection of malignant kidney cancer. The findings of the study have been published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
"Renal cell carcinoma, a malignant tumor arising from the kidney, is one of the most difficult forms of cancer to detect and treat properly because it remains silent until disseminating to other organs," said Nam Hoon Cho, M.D., of the Department of Pathology at Yonsei University Health System in Seoul, Korea. "Furthermore, because imaging, which is high-cost, is seldom performed without any specific reasons, developing a blood-tumor biomarker is a great chance to detect the silent killer."
The new immunoassay developed by Cho and colleagues from Genomine Inc. measured the levels of three potential biomarkers for kidney cancer: nicotinamide N-methyltransferase (NNMT), L-plastin (LCP1) and nonmetastatic cells 1 protein (NM23A).
Next, the researchers tested the ability of the immunoassay to distinguish plasma samples from healthy controls and patients with kidney cancer using the same 189 plasma samples already tested. The results indicated that the three-marker assay was highly accurate. When it correctly identified 90 percent of the samples from healthy controls, it also correctly identified 94.4 percent of the samples from patients with kidney cancer.
To validate the accuracy of the test, the researchers blind tested an additional 100 plasma samples from 73 healthy controls and 27 patients with kidney cancer. In this analysis, 67 of the samples from the 73 healthy controls and all of the samples from patients with kidney cancer were classified correctly.
"If this biomarker is truly valid and accurate to detect renal cell carcinoma, a number of patients with renal cell carcinoma could potentially be saved through early diagnosis," Cho said.
Cho and colleagues hope that this biomarker will soon be commercially available. They are currently working toward approval by the U.S. Food and Drug Administration.