A panel of angiogenic factors for early bladder cancer detection: enzyme immunoassay and Western blot.

Abstract

Angiogenesis is tightly regulated by a large number of pro-angiogenic factors, including vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor and angiogenin. We adapted and evaluated the measurement of these factors using enzyme-linked immunosorbent assay and compared the results with Western blot and voided urine cytology. This study included 240 patients diagnosed with bladder carcinoma, 108 with benign bladder lesions and 110 healthy individuals who served as controls. All participants underwent serological schistosomiasis antibody assay in serum, urine cytology and estimation of angiogenic factors in voided urine. Intra-assay and interassay CVs of the investigated markers were 10.3 to 12.3 and 10 to 13.7, respectively. The recovery rate of the added angiogenic factor to the urine pool was 98% to 103%, 97% to 103%, 98% to 104% and 97% to 100% for vascular endothelial growth factor, basic fibroblast growth factor, angiogenin and hepatocyte growth factor, respectively. The concordance rate with Western blot was 97.5%. The levels and positive rates of urinary angiogenic markers and urine cytology were significantly higher in the malignant group than in the benign and healthy groups. Basic fibroblast growth factor increased significantly in bladder squamous cell carcinoma cases. Moreover, basic fibroblast growth factor and hepatocyte growth factor significantly correlated with tumor grade. Angiogenic markers showed significant association with clinical stage. Quantitative measurement of urinary angiogenic factors in voided urine samples by enzyme-linked immunosorbent assay was reliable. The sensitivity of basic fibroblast growth factor and hepatocyte growth factor was superior to that of the other investigated markers and of cytology in low grade and early stage cases, suggesting their convenience as sensitive, noninvasive diagnostic and screening tools for bladder cancer.