Natural History of Complex Renal Cysts: Clinical Evidence Supporting Active Surveillance

To evaluate intervention rates, progression and cancer-specific survival outcomes of patients with complex renal cysts in a single center experience.

A radiology data-mining system (Montage; Montage Healthcare Systems, Philadelphia, PA, USA) was used to retrospectively identify all reported cases of "complex renal cyst" in our institution (2001-2013).

Primary end points were overall (OS) and cancer specific survival (CSS). Secondary endpoints included radiographic progression and upgrading, clinical progression, and final histology on surgical pathology.

336 patients were identified with a "complex renal cyst", of which 185 (55.1%), 122 (36.3%), and 29 (8.6%) had Bosniak IIF, III and IV cysts, respectively. Median follow-up was 67.1 (34.4-101.6) months. Of the 332 patients with follow-up, there was one cancer-specific death (0.3%) and overall mortality was 6.2%. Ten (5.4%), 37 (30.3%) and 18 (62.1%) of the Bosniak IIF, III and IV patients underwent either surgical or ablative intervention, respectively. Indication for intervention was predominantly age (intervention 50.1±15.9, no intervention 62.5±13.9) and complexity. Surgery with radical (23 [35%]) or partial nephrectomy (37 [57%]) was most common, and favorable final pathology was identified. Two treated patients experienced recurrence during follow-up. When excluding VHL patients, cancer specific survival was 100%.

Cancer-specific survival and overall survival for patients with Bosniak IIF-IV renal cysts was very high; with only one cancer-specific death. There were no cancer deaths recorded in those that did not undergo intervention. Reconsideration of management guidelines for complex renal cysts is warranted, particularly consideration for initial surveillance in Bosniak III cysts.

The Journal of urology. 2017 Sep 20 [Epub ahead of print]

Thenappan Chandrasekar, Ardalan E Ahmad, Kamel Fadaak, Kartik Jhaveri, Jaimin R Bhatt, Michael A S Jewett, Antonio Finelli

Department of Surgical Oncology, Division of Urologic Oncology, Princess Margaret Cancer Centre, University Health Network and the University of Toronto, Toronto, Ontario, Canada., Joint Department of Medical Imaging, Princess Margaret Cancer Centre, University Health Network, and the University of Toronto, Toronto, Ontario, Canada., Department of Urology, University Hospital Ayr, Ayr, UK., Department of Surgical Oncology, Division of Urologic Oncology, Princess Margaret Cancer Centre, University Health Network and the University of Toronto, Toronto, Ontario, Canada. Electronic address: .

Included In: Badrinath Konety, MD 2018 AUA Presentation: Journal of Urology: Top Papers in Bladder and Renal Cancer