Growth and renal function dynamics of renal oncocytomas in patients on active surveillance

Abstract

To study the natural history of renal oncocytomas and address indications for intervention by determining how growth is associated with renal function over time, the reasons for surgery and ablation, and disease-specific survival. Patients and MethodsThe study was conducted in a retrospective cohort of consecutive patients with renal oncocytoma on active surveillance reviewed at the Specialist Centre for Kidney Cancer at the Royal Free London NHS Foundation Trust (2012 to 2019. Comparison between groups was performed using Mann-Whitney U-tests and chi-squared tests. A mixed-effects model with a random intercept for patient was used to study the longitudinal association between tumour size and estimated glomerular filtration rate (eGFR). ResultsLongitudinal data from 98 patients with 101 lesions were analysed. Most patients were men (68.3%) and the median (interquartile range [IQR]) age was 69 (13) years. The median (IQR) follow-up was 29 (26) months. Most lesions were small renal masses, and 24% measured over 4 cm. Over half (64.4%) grew at a median (IQR) rate of 2 (4) mm per year. No association was observed between tumour size and eGFR over time (P = 0.871). Nine lesions (8.9%) were subsequently treated. Two deaths were reported, neither were related to the diagnosis of renal oncocytoma. ConclusionNatural history data from the largest active surveillance cohort of renal oncocytomas to date show that renal function does not seem to be negatively impacted by growing oncocytomas, and confirms clinical outcomes are excellent after a median follow-up of over 2 years. Active surveillance should be considered the 'gold standard' management of renal oncocytomas up to 7cm.

Renal Oncocytoma: The Diagnostic Challenge to Unmask the Double of Renal Cancer

“…Oncocytomas represent the most common surgically removed benign renal tumors, with an incidence ranging from 4% to 7% of all kidney surgeries for neoplasms [ 184 ]. This high rate of surgery for a non-malignant process is the result of the underuse of percutaneous renal surgery and from the inability of the current radiological techniques to distinguish between malignant and benign lesions with an acceptable degree of accuracy [ 184 , 185 ].…”

“…Oncocytomas represent the most common surgically removed benign renal tumors, with an incidence ranging from 4% to 7% of all kidney surgeries for neoplasms [ 184 ]. This high rate of surgery for a non-malignant process is the result of the underuse of percutaneous renal surgery and from the inability of the current radiological techniques to distinguish between malignant and benign lesions with an acceptable degree of accuracy [ 184 , 185 ]. Moreover, in the urological scenario, clinicians are still divided on the interventional management of oncocytoma, with a high percentage of surgeons who prefer to operate rather than considering a period of surveillance [ 186 ].…”

Benefit and Harm of Active Surveillance for Biopsy-proven Renal Oncocytoma: A Systematic Review and Pooled Analysis

“…A total of 2862 initial searches were identified. After duplicate removal, title and abstract screening, and full-text review, ten studies were included for qualitative and quantitative analyses [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] .

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“…Six studies including 433 patients reported the definitive treatment rates from AS to definitive treatment [12] , [13] , [14] , [17] , [18] , [19] . In the pooled studies, the median follow-up was 34.5 mo (95% confidence interval [CI] 30.6–38.4).…”

“…Indications for invasive treatment were reported in five studies [12] , [13] , [17] , [18] , [19] involving a total of 49/334 patients who underwent definitive treatment (surgical excision or ablative treatment). When reported, indications for definitive treatment were rapid tumor growth ( n = 32/49, 65%), patient request ( n = 6/49, 13%), onset of symptoms ( n = 5/49, 10%), change in tumor shape ( n = 4/49, 8%), and large tumor volume at baseline (>100 and 87 mm, n = 2/49, 4%).…”