Upcoming event

Decision-making and management strategies for patients with bilateral synchronous non-metastatic renal masses: Insights from a multi-centre European dataset

Introduction & Objectives

The optimal management strategy for patients with bilateral synchronous non-metastatic renal masses (BSRM) is still controversial. Thus, evaluating how decision-making is pursued in such challenging cases is a distinct unmet need. We aimed to evaluate the pattern of care and outcomes in these patients based on a multi-centre European dataset.

Materials & Methods

Data from consecutive patients with BSRMs managed with active surveillance (AS) and/or ablative therapies (AT) and/or surgery at 8 referral institutions between 1993-2020 were collected. The primary objectives were: a) to evaluate the decision-making regarding non-surgical management; b) to assess the proportion of simultaneous vs staged surgery, as well as the type of surgery, c) to evaluate histopathological and oncologic outcomes of patients undergoing surgery.


Out of 134 patients, 79.1% were males. The median Charlson Comorbidity Index was 3 (IQR 2-4). Overall, 5.2% of patients had either a familial history of renal cell carcinoma (RCC) or a hereditary syndrome. Median age and eGFR at diagnosis were 62 (IQR 54-71) years and 82 (IQR 68-91) ml/min, respectively. The median size of the left and right renal masses was 4 cm (IQR 3-7) and 4 cm (IQR 3-6), respectively. Tumor biopsy was performed in 10 cases (7.5%). The management options included: AS for both BSRMs in 0.7% patient; AS and surgery in 3.7%; AS with delayed intervention (DI) and AT in 1.5%; AS with DI and surgery in 6.0%; AS with DI for both BSRMs in 1.5%; AT + surgery in 5,2%; and bilateral surgery in 81.3%. Among patients undergoing bilateral surgery (n=109), a staged approach was chosen in 85. Among these patients, 51/85 treated the lower complexity tumour first, while 34 the higher complexity tumour first. Among patients undergoing simultaneous surgery (n=24/109), the surgical strategy was: PN / PN in 75% of patients, PN / RN in 12.5% and RN / RN in 8.3%. Among patients undergoing staged surgery (n=85/109), the surgical strategy was: PN/PN in 80%, PN / RN in 16.5% and RN / RN 3.5% of cases. Overall, we found a discordant histology between the two renal masses in 26/109; among these, 7/26 (27%) harbored a malignant renal mass on eone side a benign renal mass on the other. Among cases with concordant histology (n=83/109, 76%), 8/83 (9.6%) harbored a bilateral benign mass. In the cohort of patients undergoing bilateral surgery, at a median follow-up of 44 months, 8 developed local recurrence, 6 were alive with evidence of disease, 4 died due to RCC, 2 died due to other causes.


Decision-making and management of BSRMs, including surgical strategy, is highly heterogenous across institutions and include both AS (with or without DI), AT and, predominantly, surgery. In addition, we found differences across Centres in the choice of simultaneous vs staged surgery in candidates for bilateral intervention.