Development of a multiplex RNA urine test for the detection and stratification of transitional cell carcinoma of the bladder.

Abstract

New markers that enable the percentage of transitional cell carcinomas (TCC) of the bladder that are diagnosed before invasion of the bladder muscle layers to be increased would reduce the morbidity and mortality associated with this disease. The purpose of this study was to develop a simple, accurate urine test based on mRNA markers and simple gene signatures that (a) could detect TCC before muscle invasion while maintaining high specificity in patients with hematuria or urinary tract infections and (b) identify patients most likely to have grade 3 or stage > or =T1 disease. RNA markers with high overexpression in stage Ta tumors and/or T1 to T4 tumors but low expression in blood or inflammatory cells were characterized by quantitative reverse transcription-PCR using 2 mL of voided urine from 75 TCC patients and 77 control patients with other urological diseases. A combination of the RNAs CDC2, MDK, IGFBP5, and HOXA13 detected 48%, 90%, and 100% of stage Ta, T1, and >T1 TCCs, respectively, at a specificity of 85%. Detection of Ta tumors increased to 60% for primary (non-recurrent) Ta tumors and 76% for Ta tumors > or =1 cm in diameter. Test specificity was 80% for the 20 control patients with urinary tract infections. The combination of CDC2 and HOXA13 distinguished between grade 1 to 2 TCCs and grade 3 or stage > or =T1 TCCs with approximately 80% specificity and sensitivity. Simple gene expression signatures can be used as urine markers for the accurate detection and characterization of bladder cancer.