Measuring the levels of three serum proteins can detect kidney cancer with high accuracy, according to a study published in Cancer Epidemiology, Biomarkers & Prevention (2013;22:390-398).
Dong Su Kim, from Genomine Inc. in Pohang, South Korea, and colleagues assessed the accuracy of a test for early detection of renal cell carcinoma based on plasma levels of nicotinamide N methyltransferase (NNMT), L-plastin (LCP1), and non-metastatic cells 1 protein (NM23A) in 102 control patients who were healthy or had benign tumors and in 87 patients with kidney cancer.
The researchers found that the levels of all three biomarkers were significantly higher in patients with kidney cancer. Using a cut-off of 147 pg/mL for NNMT, 12,974 pg/mL for LCP1, and 1,230 pg/mL for NM23A, the sensitivity for detecting kidney cancer was 94.4 percent at 90 percent specificity. The cut-offs correctly classified 67 of 73 additional control patients and 27 of 27 additional kidney cancer patients. Including all patients, at a specificity of 90%, the sensitivity was 95.7% and the diagnostic accuracy (area under the curve) was 0.932. The three-biomarker assay had a positive predictive value of 87.2% and a negative predictive value of 97%.
“The composite assay with NNMT, LCP1, and NM23A was a promising novel serum marker assay for the early detection of malignant kidney tumors covering subtypes of renal cell carcinoma with high diagnostic characteristics,” Kim and colleagues conclude.