Urinary transcript quantitation of CK20 and IGF2 for the non-invasive bladder cancer detection.

PURPOSE: Cytokeratin 20 (CK20) and insulin-like growth factor 2 (IGF2) were previously proposed to be elevated in clinical samples from patients with bladder cancer (BCa). A two cohort design validation study was used to assess the relevance for BCa detection by transcript quantitation of both markers in urine samples. Their diagnostic value was assessed in comparison with voided urine cytology (VUC). METHODS: RNA isolation was carried out using cellular sediments of urine samples from 196/103 histologically positive BCa patients, as well as 97/50 control subjects for the test (TC) and validation cohort (VC), respectively. Urinary transcript levels of CK20 and IGF2 were determined by qPCR. RESULTS: Relative transcript levels were significantly elevated 3.4/11-fold for CK20 and 188/64-fold for IGF2 (p < 0.001) in urine sediments of BCa patients compared to controls in the TC and VC, respectively. In a combined analysis, the resulting sensitivity (SN) (SNTC: 77.9; SNVC: 90.3%) and specificity (SP) (SPTC: 88.0; SPVC: 84.0%) were similar to that of VUC. The sensitivity of VUC in combination with CK20 and IGF2 was considerably increased (SNTC: 94.6; SNVC: 93.2%) while specificity was reduced (SPTC: 72.0; SPVC: 82.0%) compared to VUC alone in the test and validation cohort. CONCLUSIONS: Transcript levels of IGF2 and CK20 enabled the detection of BCa with a diagnostic performance similar to VUC. Combined analysis of voided urine cytology together with altered transcript levels of CK20 and IGF2 enhanced sensitivity, but did not improve overall test performance.

Urinary insulin-like growth factor 2 identifies the presence of urothelial carcinoma of the bladder.

OBJECTIVE: To examine urinary insulin-like growth factor 2 (IGF-2) levels in patient urine samples and determine the potential of IGF-2 as a marker for the presence of urothelial carcinoma of the bladder (UCB). PATIENTS AND METHODS: The current gold standard for diagnosis of UCB is cystoscopy and cytological analysis. The identification of an accurate urine marker for UCB with the potential to replace unnecessary cystoscopy would benefit patients with UCB and others investigated after detecting haematuria. In the present study, we analysed 65 urine samples, and optimized an enzyme-linked immunosorbent assay-based approach to measure urinary levels of IGF-2. RESULTS: Based on a threshold of 5.4 ng/mL, patients with UCB have significantly elevated levels of urinary IGF-2 (P = 0.009) and this difference remained significant after adjustment for age and sex (P = 0.04). Sensitivity and specificity values of 80% and 52%, respectively, were determined for urinary IGF-2 alone and when combined with nuclear matrix protein 22 (NMP22; an approved biomarker for detection of UCB). There was a positive correlation between urinary IGF-2 levels and NMP22 levels in patient urine samples and the combined assay improved the detection of UCB (sensitivity 85% and specificity 52%). CONCLUSION: Substantiated evidence has identified IGF-2 as a valuable marker for UCB. In addition, the novel observations of the present study have shown that aberrant levels of IGF-2 occurring in the presence of UCB, can now be determined through a simple and inexpensive urine assay.