[Optimization biomarkers in the surveillance of non muscle invasive bladder cancer.]

Bladder cancer is thefifth most common tumor in the world. Moreover, it isone of the most expensive due to its high recurrencerate. Urinary biomarkers for surveillance of non muscleinvasive bladder cancer is a promising and growingfield due to the invasiveness of the actual methods, basedon cystoscopy and cytology. Although current EuropeanGuidelines only consider the use of biomarkersin the low risk scenario as an alternative to cystoscopywhen the patient declines invasive methods for the follow-up after surgery, there is increasing evidence oftheir safety in high risk tumors.

We have performeda review of the main urinary biomarkers, includingFDA-approved ones, protein-based and genetic biomarkers.We have also described the different options to incorporatethe biomarkers in the clinical practice.

There are not randomized control trialscomparing any biomarker with the gold standard follow-up. Most of the papers published so far are cohortstudies, limitating the evidence of the results. Biomarkerscan be used as an alternative of cystoscopy, in a noninvasive follow-up, or alternating both tests. There arefew economical studies comparing both options, but theevidence supports the efficiency of the main biomarkers.

Cystoscopy and cytology are the goldstandard for non muscle invasive bladder cancer surveillance.2021 European Guidelines suggest, for the firsttime, an alternative use of biomarkers in a concrete lowgrade scenario to avoid invasive explorations to patientswith low risk of progression. Paradoxically, biomarkers(mainly genetic ones) have a very good profile of sensitivityand negative predictive value in the high risk scenario.Although there is increasing evidence to supporttheir implementation, the lack of fase IV trials hinderstheir daily use.