The objective of this study was to assess the value of fluorescence in situ hybridization (FISH) for predicting early recurrence in intermediate-, and high-risk NMIBC patients treated with BCG.

A systematic review was conducted using MEDLINE, Embase and the Cochrane library. Individual patient data (IPD) from prospective observational studies evaluating FISH in patients treated with BCG were included. A two-stage IPD meta-analysis was carried out to assess the value of FISH for predicting tumor recurrence after BCG induction therapy.

From four studies IPD were obtained of 422 patients, and 408 patients included in final analysis with a median follow-up of 18.8 months. The hazard ratio for recurrence when FISH was positive was pre-BCG (t0) 1.20 (95% CI: 0.81-1.79), at six weeks (t1) 2.23 (95% CI: 1.31-3.62), at three months (t2) 3.70 (95% CI: 2.34 – 5.83), and at six months (t3) 23.44 (95% CI: 5.26-104.49).

A positive FISH test post-BCG correlates with a higher risk for a tumor recurrence. FISH could aid urologists in risk stratification and counseling of patients. Based on both HR and its narrowest CI, the preferred timing for FISH is three months following TURBT. This is also in time for patients who fail to respond to induction therapy to enter clinical trials, or to change treatment strategy.

The Journal of urology. 2019 Sep 24 [Epub ahead of print]

Esmee Iml Liem, J R Oddens, Rwm Vernooij, R Li, A M Kamat, C P Dinney, L Mengual, A Alcaraz, L Izquierdo, S Savic, G N Thalmann, L Bubendorf, R J Sylvester, T M de Reijke

Amsterdam UMC, Department of Urology, University of Amsterdam, The Netherlands., Netherlands Comprehensive Cancer Organisation (IKNL), Department of research, Utrecht, The Netherlands., MD Anderson Cancer Center, Department of Urology, USA., Hospital Clinic, Institut d’Investigacions Biomediques August Pi I Sunyer, Laboratory and department of Urology, Spain., Institute of Pathology, University Hospital, Basel, Switzerland., Department of Urology, University Hospital, Bern, Switzerland., EAU Guidelines Office, Brussels, Belgium.