BACKGROUND Fifty percent of patients with muscle-invasive bladder cancer (MI-BC) die from their disease and current chemotherapy treatment only marginally increases survival. Novel therapies... Show moreBACKGROUND Fifty percent of patients with muscle-invasive bladder cancer (MI-BC) die from their disease and current chemotherapy treatment only marginally increases survival. Novel therapies targeting receptor tyrosine kinases or activated oncogenes may improve outcome. Hence, it is necessary to stratify patients based on mutations in relevant oncogenes. Patients with non-muscle-invasive bladder cancer (NMI-BC) have excellent survival, however two-thirds develop recurrences. Tumor specific mutations can be used to detect recurrences in urine assays, presenting a more patient-friendly diagnostic procedure than cystoscopy. METHODOLOGY/PRINCIPAL FINDINGS To address these issues, we developed a mutation assay for the simultaneous detection of 19 possible mutations in the HRAS, KRAS, and NRAS genes. With this assay and mutation assays for the FGFR3 and PIK3CA oncogenes, we screened primary bladder tumors of 257 patients and 184 recurrences from 54 patients. Additionally, in primary tumors p53 expression was obtained by immunohistochemistry. Of primary tumors 64% were mutant for FGFR3, 11% for RAS, 24% for PIK3CA, and 26% for p53. FGFR3 mutations were mutually exclusive with RAS mutations (p = 0.001) and co-occurred with PIK3CA mutations (p = 0.016). P53 overexpression was mutually exclusive with PIK3CA and FGFR3 mutations (p≤0.029). Mutations in the RAS and PIK3CA genes were not predictors for recurrence-free, progression-free and disease-specific survival. In patients presenting with NMI-BC grade 3 and MI-BC, 33 and 36% of the primary tumors were mutant. In patients with low-grade NMI-BC, 88% of the primary tumors carried a mutation and 88% of the recurrences were mutant. CONCLUSIONS/SIGNIFICANCE The mutation assays present a companion diagnostic to define patients for targeted therapies. In addition, the assays are a potential biomarker to detect recurrences during surveillance. We showed that 88% of patients presenting with low-grade NMI-BC are eligible for such a follow-up. This may contribute to a reduction in the number of cystoscopical examinations. Show less
Zuiverloon, T.C.M.; Aa, M.N.M. van der; Kwast, T.H. van der; Steyerberg, E.W.; Lingsma, H.F.; Bangma, C.H.; Zwarthoff, E.C. 2010
PURPOSE Mutations in the fibroblast growth factor receptor 3 (FGFR3) have been found in 70% of the low-grade non-muscle-invasive bladder cancer (NMI-BC) tumors. We aim to determine the potential of... Show morePURPOSE Mutations in the fibroblast growth factor receptor 3 (FGFR3) have been found in 70% of the low-grade non-muscle-invasive bladder cancer (NMI-BC) tumors. We aim to determine the potential of FGFR3 mutation analysis on voided urine to detect recurrences during surveillance of patients with low-grade NMI-BC. EXPERIMENTAL DESIGN FGFR3 mutation status of the study inclusion tumor was determined from 200 low-grade NMI-BC patients. Patients with an FGFR3-mutant inclusion tumor were selected for analysis and monitored by cystoscopy, and voided urine samples were collected. FGFR3 mutation analysis was done on 463 prospectively collected urines. Sensitivity and predictive value of the assay were determined for detection of concomitant recurrences. Longitudinal and Cox time-to-event analyses were done to determine the predictive value for detection of future recurrences. RESULTS Median follow-up was 3.5 years. The sensitivity of the assay for detection of concomitant recurrences was 26 of 45 (58%). Of the 105 positive urine samples, 85 (81%) were associated with a concomitant or a future recurrence. An FGFR3-positive urine was associated with a 3.8-fold (P < 0.0001) higher risk of having a recurrence in the Cox analysis. In contrast, only 41 of 358 (11%) FGFR3-negative urine samples were associated with a recurrence. Positive predictive value increased from 25% to 90% in patients having consecutive FGFR3-positive urine tests. CONCLUSIONS FGFR3 mutation analysis on voided urine is a simple and noninvasive diagnostic method for detection of recurrences during surveillance of patients presenting with a low-grade FGFR3-mutant NMI-BC tumor. Show less
Aa, M.N.M. van der; Steyerberg, E.W.; Bangma, C.; Rhijn, B.W.G. van; Zwarthoff, E.C.; Kwast, T.H. van der 2010
PURPOSE: We evaluated the influence of knowledge of urine test outcome on the accuracy of cystoscopy (diagnostic review bias) during surveillance in patients with low grade, nonmuscle invasive... Show morePURPOSE: We evaluated the influence of knowledge of urine test outcome on the accuracy of cystoscopy (diagnostic review bias) during surveillance in patients with low grade, nonmuscle invasive urothelial carcinoma. MATERIALS AND METHODS: We performed a prospective, single-blind, randomized, multicenter clinical trial of surveillance by microsatellite analysis urine test in 448 patients with nonmuscle invasive (pTa, pT1, G1, G2) urothelial carcinoma. Positive or negative urine test results were only communicated to the urologist in the intervention arm of 226 patients, in which cystoscopy was done if the test was positive, and at 3, 12 and 24 months. Urine test results were not communicated in the control arm of 222 patients who underwent standard 3-month cystoscopy. The primary outcome measure was the number of histologically proven bladder cancer recurrences. RESULTS: At a median 34-month followup 218 recurrences were detected in the intervention arm compared to 163 in the control arm (p <0.001). Of 131 cystoscopies done with knowledge of a positive urine test 42 recurrences were detected. Only 6 recurrences were found in the 120 cystoscopies done without information on the positive test result (chi-square p <0.001). There was no difference in recurrence detection when urine test results were negative in the intervention and control arms (18 of 260 patients or 7% and 18 of 326 or 6%, respectively, p = 0.45). CONCLUSIONS: Diagnostic review bias should be considered in the evaluation of point of care urine tests for bladder cancer monitoring. Awareness of a positive urine test result significantly improves the urothelial carcinoma detection rate using cystoscopy. Show less
