Xpert Bladder Monitor: a Non-Invasive Follow-Up Tool for Detecting Relapse in High Grade or High Risk Bladder Cancer

Main objectives: Qualitative and quantitative monitoring of recurrences in patients with a previous diagnosis of high-grade bladder cancer at high risk of persistence/recurrence. Endpoints: Presence or absence of mRNA in urine with a dichotomous result; concordance between Xpert BM and histopathological examination Clinical relevance: reduces by half the number of (invasive) cystoscopies during follow-up. The non-invasive nature of the test could improve patient compliance with follow-up. Interventional study because it would reduce by half the number of cystoscopies during follow-up of bladder cancer which is considered the gold standard in the follow-up of this tumor. However, these markers are already CE validated and described in the European guidelines and for this reason the risk would be low.

STUDY DESIGN This prospective study is designed to assess the use of Xpert Bladder Monitor during the follow-up of patients with high grade bladder cancer. As per the guidelines, the study involves the following schedule: * At the first outpatient check-up after diagnosis, patients will undergo cystoscopy and urinary cytology at 3 months. * As follow-up continues, at 6 months, Xpert Bladder Monitor and 3 days urinary cytology will be performed instead of cystoscopy. * As follow-up continues, at 9 months, standard monitoring with cistoscopy and 3 days cytology on voided urine is provided . * As follow-up continues, at 12 months, another Xpert Bladder Monitor and 3 days urinary cytology will be performed. The same schedule will be followed for the second year of follow-up. In the event of a positive Xpert Bladder Monitor result during follow-up, a cystoscopy will be scheduled. The study aims to enroll 50 patients for an initial follow-up of 2 years, alternating between cystoscopy and Xpert Bladder Monitor: this will involve 200 tests. The study expects to enroll patients in approximately 24 months, and with a 24-month follow-up, the study will be completed within 48 months. During the study, the possibility of extending it to a 5-year follow-up with six-monthly checks will be evaluated.The potential risk is to is not recognize a disease recurrence during follow-up at an early convenient stage. The potential benefits are related to the possibility of avoid an invasive procedure like cystoscopy which is expensive, with potential harms, surgeon-related and with a long waiting list. If patient has a positive Xpert Bladder Monitor, a cystoscopy will be performed within 30 days to verify the result. ELEGIBILITY CRITERIA Participants will be recruited to the study only if they meet all of the inclusion criteria and none of the exclusion criteria. 4.1 Inclusion Criteria * Age ≥ 18 years * Has a legally acceptable representative capable of understanding the informed consent document and providing consent on the participant's behalf * NMIBC high grade or high risk (already subjected to or currently undergoing treatment with BCG). * No contraindications to surgery 4.2 Exclusion Criteria * Inability or unwillingness of the participant or their legal representative to provide written informed consent * Absolute contraindications to surgery or cystoscopy * Patients who have previously participated in clinical protocols involving chemotherapy drugs or immunotherapy * Patients with multiple recurrent tumors eligible for cystectomy or Muscle-Invasive Bladder Cancer (MIBC)