Three Biomarkers Identify Early Stage Kidney Cancer

An innovative immunoassay that tests for the presence of three biomarkers appears to be a valid screening method for the early detection of malignant kidney cancer.

The immunoassay measured the levels of three potential biomarkers for kidney cancer: nicotinamide N-methyltransferase (NNMT), L-plastin (LCP1), and nonmetastatic cells 1 protein (NM23A).

Scientists at the Yonsei University Health System (Seoul, South Korea) developed and validated bead-based sandwich immunoassays using bead-conjugated capture antibodies, biotin-labeled detection antibodies, and phycoerythrin-labeled streptavidin (Invitrogen; Carlsbad, CA, USA). They measured concentrations of NNMT, LCP1 and NM23A in 189 plasma samples from 102 healthy controls and patients with benign tumors and 87 patients with kidney cancer using this assay.

Plasma levels indicated that all three biomarkers were highly elevated in patients with kidney cancer. For example, the median level of NNMT concentration in healthy controls was 68 pg/mL compared with 420 pg/mL for patients with kidney cancer. The median concentration of LCP1 in control individuals and patients with kidney cancers was 10,384 and 13,789 pg/mL, respectively and this difference was significant. The plasma concentration of NM23A was also significantly higher in patients with kidney tumor than in controls with a median concentration of 780 pg/mL in control individuals and 3,442 pg/mL in patients with kidney cancer.

To validate the accuracy of the test, the investigators 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. Nam Hoon Cho, MD, the senior author said, “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.”

Dr. Cho and his colleagues at Genomine, Inc. (Pohang, Korea) hope that this biomarker will soon be commercially available. They are currently working toward approval by the US Food and Drug Administration (FDA; Silver Springs, MD, USA). The study was published on March 10, 2013, in the journal Cancer Epidemiology, Biomarkers & Prevention.

Related Links:
Yonsei University Health System
Invitrogen
Genomine Inc.