The Utility of Urine Cytology in Predicting Recurrence following Intravesical Therapy for Non‐Muscle Invasive Bladder Cancer - Expert Commentary

Urine cytology plays an essential role in detecting patients who are at high risk for disease recurrence following non-muscle invasive bladder cancer (NMIBC) treatment. A recent study Gupta et al. in the World Journal of Urology evaluated the accuracy of urine cytology in detecting recurrence and progression following therapy for NMIBC. The investigators included 90 cytology samples and biopsy specimens from 76 patients who were diagnosed with NMIBC between 2013 and 2016 and received intravesical treatment. The majority of samples 80% (71) were taken from patients treated for high-grade disease, and 20% (18) from patients treated for low- grade disease. 56/90 samples came from patients who received bacillus Calmette–Guerin (BCG) induction therapy and 34/90 from patients who received second-line intravesical gemcitabine/docetaxel, mitomycin, or BCG/interferon. The accuracy of urine cytology was compared to systemic biopsies.

The authors found that urine cytology detected high- grade disease in 8/15 patients with high-grade disease biopsy results who received induction BCG. In this group, cytology had a sensitivity of 53% (95% CI 27–79%), a specificity of 95% (95% CI 84–99%), a positive predictive value of 80% (95% CI 44–98%), and a negative predictive value of 85% (95% CI 71–94%).In the high grade and suspicious for high grade, urine cytology has a sensitivity of 67% (95% CI 38–88%) and specificity of 88% (95% CI 74–96%).

The authors conclude that while urinary cytology maintains a high specificity following intravesical therapy, it has low sensitivity for high-grade urothelial carcinoma. This study highlights the need for biomarkers that predict recurrences of NMIBC following intravesical BCG. Cell-free DNA technology is a promising developing technology in this space.

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

References:

1. Gupta M, Milbar N, Tema G, Pederzoli F, Chappidi M, Kates M, VandenBussche CJ, Bivalacqua TJ. Impact of intravesical therapy for non-muscle invasive bladder cancer on the accuracy of urine cytology. World J Urol. 2019 Oct;37(10):2051-2058. DOI: 10.1007/s00345-018-02624-3. Epub 2019 Jan 23.

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