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Comparison of Surgery and Active Surveillance in the Treatment of Bosniak III Renal Cysts

A Prospective Multicenter Trial Comparing Surgery Versus Active Surveillance In Patients With Bosniak 3 Renal Cystic Masses, A NoRenCa And FinnKidney Study

Status
Not yet recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04670887
Enrollment
200
Registered
2020-12-17
Start date
2021-03-15
Completion date
2036-01-11
Last updated
2021-02-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cystic Renal Disease, Kidney Cancer, Surgery

Keywords

Bosniak classification, Active surveillance, Renal cystic mass, Cystic renal cell carcinoma

Brief summary

The incidence of renal cysts is rising due to increased abdominal imaging. Renal complicated cysts have been traditionally classified according to the Bosniak classification, which distinguishes cystic masses by specific features of walls and septa. The categories I and II are benign and class IIF most probably benign but needs a short radiological follow-up. Categories III and IV have been traditionally operated due to the increased risk of renal cell carcinoma. However, recently published studies show that approximately 50% of the operated Bosniak III cystic masses are benign, which means that half of the cases are overtreated by surgery. It has also been shown that surgical pathology of stable Bosniak IIF cysts is malignant in less than 1%, while the cysts, which are upgraded to higher Bosniak classes will show malignant surgical pathology in 85%. So far, there is lack of prospective data on active surveillance in Bosniak III cystic masses. The aim of the study is to compare active surveillance and surgery in patients with Bosniak III renal cystic masses. Patients will be randomized in active surveillance or immediate surgical excision of a cystic mass. In the active surveillance group, patients are followed according to the study protocol for 10 years and treated with delayed surgery if the cystic mass upgrades into Bosniak IV/solid, becomes symptomatic or grows over a preclassified threshold. The primary objective is to compare surgical pathology between patients treated with immediate surgery versus delayed surgery. According to recent retrospective data, active surveillance of Bosniak III cystic masses is reasonable and oncologically safe. Therefore a prospective randomized controlled trial is needed to get high level evidence to support a change in the treatment strategy. The study may significantly reduce unnecessary operations performed in patients with Bosniak III cystic masses.

Interventions

Delayed surgery is performed if cystic mass radiologically upgrades into Bosniak 4 or solid mass in the active surveillance.

Partial or radical nephrectomy is performed as treatment of Bosniak 3 cystic mass

Sponsors

Helsinki University Central Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
50 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

* A sporadic single CM of Bosniak 3 according to the Bosniak Classification v.2019 is diagnosed with CT or MRI * Maximal diameter of CM 10-70 mm * Age ≥50 years * ECOG performance status \<2 * Life expectancy ≥5 years * Patient is fit to undergo surgery and AS. * Patient understands a national language or English * Signed informed consent

Exclusion criteria

* Genetic syndromes associated with RCC * Previously or simultaneously diagnosed and pathologically verified RCC * Previously or simultaneously radiographically identified solid mass or CM of Bosniak 3/4 with diameter ≥10mm * The target CM of Bosniak 3 has progressed in sequential imaging from Bosniak 1-2F * Presence of radiographic findings which are suspect for nodal or distant metastatic disease * Symptomatic CM * Kidney insufficiency (GFR\<55 ml/min/1,73m2) * Patients who have contraindications for both CT and MRI imaging. . Anatomically solitary kidney

Design outcomes

Primary

MeasureTime frame
Malignancy rate in surgical pathologyFrom date of randomization until the date of surgery, assessed up to 120 months

Secondary

MeasureTime frame
Cancer specific survivalFrom date of randomization until the date of death due to renal cancer, assessed up to 120 months
Progression-free survivalFrom date of randomization until the date of first documented progression, assessed up to 120 months
Overall survivalFrom date of randomization until the date of death from any cause, assessed up to 120 months

Contacts

Primary ContactHarry Nisén, Adj. professor
harry.nisen@hus.fi+35894711
Backup ContactJuhana Rautiola
juhana.rautiola@hus.fi+35894711

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026