Surveillance of Complex Renal Cysts - the SOCRATIC Pilot Study

STUDY DESIGN - This is a two-arm multicenter prospective observational pilot study where patients with Bosniak III or IV choosing either active surveillance or surgery will be monitored closely. OBJECTIVES - PRIMARY Validate the feasibility issues (acceptability, recruitment rate, costs, protocol adherence and implementation of imaging central review) of an observational study on the treatments of complex cysts. SECONDARY a- Validate the inclusion and exclusion criteria in regard to the feasibility of the study; b- Validate the triggers for discontinuation of AS in terms of feasibility and safety for the patients. POPULATION - For the pilot study, the intended targeted population will be patients incidentally diagnosed with a Bosniak III or IV cysts and who opted to be managed by either surgery or active surveillance. METHODOLOGY - Upon written consent, patients will be explained the followup scheme which will consist of a semi-annual visits for 1 year. To mimic the upcoming larger study and to evaluate visit feasibility issues, the baseline and the follow-up visits will consist of the following items: blood results, CT-scan result, quality of life questionnaires and medical data. Baseline (prior to study entry) and follow-up abdominal imaging (CT/MRI) suspicious for progression will be reviewed centrally by an interventional radiologist at the CIUSSSE-CHUS, to confirm Bosniak classification.

Inclusion criteria

• aged ≥18 years at the time of diagnosis
• diagnosed with a Bosniak III or IV cyst
• size of cystic component ≤7cm
• solid component ≤2 cm in maximal diameter for Bosniak IV cysts
• life expectancy >5 years (by physician's estimate)
• diagnosis ≤6 months from accrual date
• currently asymptomatic from the disease
• deemed fit enough for surgery
• willingness and ability to complete questionnaires in either French or English
• able and willing to provide informed consent.

Exclusion criteria

• history of a hereditary renal cancer syndrome
• presence of polycystic kidney disease
• systemic therapy for another malignancy within 12 months of recruitment date
• uncontrolled medical illness including infections, hypertension, arrhythmias, heart failure, or myocardial infarction/unstable angina within 6 months that would predispose to immediate surgical therapy
• metastatic disease or evidence of vascular or nodal disease
• unwillingness to undergo monitoring and imaging studies
• any contra-indication(s) to contrast-enhanced imaging (estimated glomerular filtration rate <30min/mL)