Surveillance of Complex Renal Cysts - The SOCRATIC Study

Official Title

Surveillance of Complex Renal Cysts - The SOCRATIC Study


One third of individuals aged >60 years will be diagnosed with at least one renal cyst following abdominal imaging. These cystic lesions are categorized according to the Bosniak classification which categorizes cysts according to their degree of complexity and risk of malignancy. Growing evidence suggests that a significant proportion of Bosniak III and IV cysts are benign and that the malignant ones present low metastatic potential. Since renal surgery carries substantial morbidity (20%) and potential mortality (0.5%), active surveillance has gained attention as a potential tradeoff to surgery to overcome overtreatment. Therefore, prospective studies of long-term follow-up are needed to confirm the oncologic safety of this strategy for patients with Bosniak III/IV cysts. This is an multicentre prospective observational longitudinal study. The main objective is to compare the 5-year follow-up cancer-specific survival between the active surveillance and the surgical groups.

Trial Description

Primary Outcome:

  • 5-year cancer-specific survival
Secondary Outcome:
  • 5-year overall survival
  • 2-year overall survival
  • 2-year cancer-specific survival
  • Treatment-free survival
  • Discontinuation rate
  • Tumour growth rate
  • Tumour progression rate
  • Time to tumour progression (Progression-free survival)
  • Patient and tumour characteristics in correlation with cancer-specific death
  • Patient and tumour characteristics in correlation with disease progression
  • Perceived health change over time
  • Quality of life change over time
  • Anxiety change over time
  • Health cost
Background: One in three patients over 60 years old will be diagnosed with a renal cyst following abdominal imaging. Traditionally, experts have recommended that complex cystic lesions (also known as Bosniak III
  • IV cysts) should be surgically removed, but recent evidences suggest that many are benign or have low metastatic potential. Thus, active surveillance which involves close follow-up of a patient's condition, was proposed as a tradeoff option to surgery. Design: Multicentre observational longitudinal prospective cohort study Objectives: The goal of this multicentre project is to conduct a prospective study with a 5-year follow-up to confirm the oncologic outcomes of active surveillance in the management of complex cysts. The main objectives are: 1) to compare the 5-year cancer specific survival between cysts managed by surgery and active surveillance; 2) to evaluate disease progression; 3) to evaluate patient's well-being according to each management strategy; and 4) to compare the 5-year healthcare cost of both management approaches. Study population: Patients incidentally diagnosed with a Bosniak III and/or IV cysts, who are deemed to have at least 5 years of life, and who opted to be managed by either surgery or active surveillance. (N=330) Follow-up: Patients will DECIDE if they want to have a surgery or to be followed by active surveillance. All patients will be followed as per standard of care with either semi-annual and annual visits. Research visits will serve to assess vital status and quality of life scores (through validated questionnaires). Patients on active surveillance will also be assessed for cyst progression and might be offered invasive or systemic therapy if progression is observed.

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