ABSTRACT
Retrospective studies have provided proof of principle that bladder cancer can be detected by testing for the presence of tumor DNA in urine. We have conducted a prospective blinded study to determine whether a urine-based DNA test can replace flexible cystoscopy in the initial assessment of gross hematuria. A total of 475 consecutive patients underwent standard urological examination including flexible cystoscopy and computed tomography urography, and provided urine samples immediately before (n=461) and after (n=444) cystoscopy. Urine cells were collected using a filtration device and tested for eight DNA mutation and methylation biomarkers. Clinical evaluation identified 99 (20.8%) patients with urothelial bladder tumors. With this result as a reference and based on the analysis of all urine samples, the DNA test had a sensitivity of 97.0%, a specificity of 76.9%, a positive predictive value of 52.5%, and a negative predictive value of 99.0%. In three patients with a positive urine-DNA test without clinical evidence of cancer, a tumor was detected at repeat cystoscopy within 16 mo. Our results suggest that urine-DNA testing can be used to identify a large subgroup of patients with gross hematuria in whom cystoscopy is not required. PATIENT SUMMARY: We tested the possibility of using a urine-based DNA test to check for bladder cancer in patients with visible blood in the urine. Our results show that the test efficiently detects bladder cancer and therefore may be used to greatly reduce the number of patients who would need to undergo cystoscopy.
Subject(s)
Carcinoma, Transitional Cell/diagnosis , DNA Methylation , Urinary Bladder Neoplasms/diagnosis , Urine/cytology , Adolescent , Adult , Aged , Aged, 80 and over , Carcinoma, Transitional Cell/complications , Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/urine , Cystoscopy , DNA Mutational Analysis , Female , Hematuria/etiology , Humans , Male , Middle Aged , Prospective Studies , Tomography, X-Ray Computed , Urinary Bladder Neoplasms/complications , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/urine , Urography , Young AdultABSTRACT
Molecular analysis of cells from urine provides a convenient approach to non-invasive detection of bladder cancer. The practical use of urinary cell-based tests is often hampered by difficulties in handling and analyzing large sample volumes, the need for rapid sample processing to avoid degradation of cellular content, and low sensitivity due to a high background of normal cells. We present a filtration device, designed for home or point-of-care use, which enables collection, storage and shipment of urinary cells. A special feature of this device is a removable cartridge housing a membrane filter, which after filtration of urine can be transferred to a storage unit containing an appropriate preserving solution. In spiking experiments, the use of this device provided efficient recovery of bladder cancer cells with elimination of >99% of excess smaller-sized cells. The performance of the device was further evaluated by DNA-based analysis of urinary cells collected from 57 patients subjected to transurethral resection following flexible cystoscopy indicating the presence of a tumor. All samples were tested for FGFR3 mutations and seven DNA methylation markers (BCL2, CCNA1, EOMES, HOXA9, POU4F2, SALL3 and VIM). In the group of patients where a transitional cell tumor was confirmed at histopathological evaluation, urine DNA was positive for one or more markers in 29 out of 31 cases (94%), including 19 with FGFR3 mutation (61%). In the group of patients with benign histopathology, urine DNA was positive for methylation markers in 13 out of 26 cases (50%). Only one patient in this group was positive for a FGFR3 mutation. This patient had a stage Ta tumor resected 6 months later. The ability to easily collect, store and ship diagnostic cells from urine using the presented device may facilitate non-invasive testing for bladder cancer.
