Bilateral renal cancers: oncological and functional outcomes

The current evidence on surgical management for synchronous bilateral renal tumors: results from a scoping review

PURPOSE

Synchronous bilateral renal masses (SBRM) account for a low percentage of kidney tumors, and there is no current recommendation for their management. The objective was to review evidence regarding the best surgical approach for SBRM in terms of type and timing of surgery.

METHODS

A broad literature search was performed on 28th January 2023 using Scopus, PubMed, and EMBASE. Only English papers dealing with adults were included. Meeting abstracts were excluded.

RESULTS

Twenty-four papers were accepted and included. SBRM behave less aggressively than metachronous tumors, and partial nephrectomy (PN) is the preferred therapeutic option to preserve renal function. Open, laparoscopic, and robot-assisted approaches were found to be similar in oncological outcomes, though robot-assisted surgery resulted in lower comorbidities. Same-sitting PN was demonstrated to be a safe approach, particularly in the robotic-assisted one. Finally, the same-siting and staged NSS were similar in preserving renal function.

CONCLUSIONS

PN should be the desirable treatment for SBRM whenever feasible and if patients are fit, but surgeon expertise should also be taken into the account.

Evaluation of functional outcome of bilateral kidney tumors after sequential surgery

Background

There are limited data concerning patients treated with sequential bilateral kidney surgery. Current guidelines still lack an optimal surgical sequencing approach. We evaluated renal functional outcomes after sequential partial nephrectomy (PN) and radical nephrectomy (RN) in patients with bilateral renal cell carcinoma (RCC).

Methods

A propensity score matched cohort of 267 patients (synchronous bilateral RCCs, N = 44 [88 lesions]; metachronous bilateral, N = 45 [90 lesions]; unilateral, N = 178) from two tertiary institutions were retrospectively analyzed. Synchronous bilateral RCCs were defined as diagnosis concomitantly or within 3 months of former tumor. Renal functional outcomes were defined as estimated glomerular filtration rate (eGFR) changes and de novo chronic kidney disease (CKD, stage ≥3) after surgery. Renal functional outcomes and clinical factors predicting de novo CKD were assessed using descriptive statistics and Cox regression analysis.

Results

In subgroup of bilateral RCCs, patients underwent sequential PN (N = 48), PN followed by RN (N = 8), or RN followed by PN (N = 25). Final postoperative estimated glomerular filtration rates (eGFRs) were 79.4, 41.4, and 61.2 ml/minute/1.73 m2, respectively (p = 0.003). There were significant differences in eGFR decline from baseline and de novo chronic kidney disease (CKD stage ≥ III) among groups, with PN followed by RN group showing the worst functional outcomes (all p <  0.05). Moreover, sequential PN subgroup in bilateral RCC showed significantly higher rate of de novo CKD than unilateral RCC group (13.8% vs. 6.9%, p = 0.016). On multivariate analysis, hypertension (p = 0.010) and surgery sequence (PN followed by RN, p <  0.001) were significant predictors of de novo CKD.

Conclusions

The surgery sequence should be prudently determined in bilateral renal tumors. PN followed by RN showed a negative impact on renal functional preservation. Nephron-sparing surgery should be considered for all amenable bilateral RCCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08324-3.

Case Report: Bilateral Renal Cell Carcinoma With Different Histological and Morphological Features, Clear Cell and Cystic Thyroid-Like Follicular Subtype

Thyroid-like follicular renal cell carcinoma is a rare subtype of renal cell carcinoma that has only been recently recognized, as most cases involve a solid tumor in one kidney. In this study, we report a rare case of bilateral renal cell carcinoma wherein the tumor in the left kidney was diagnosed as clear cell carcinoma, while the tumor in right kidney as thyroid-like follicular renal cell carcinoma. The difference between this case and the ones described in previous reports is that thyroid-like follicular renal cell carcinoma showed cystic changes on imaging. This suggests that when renal cystic lesions are encountered, we should consider the possibility of such rare tumors.

Active surveillance of small renal masses

Most renal masses incidentally detected by cross-sectional images are benign, being mainly cysts, and if they are malignant, they are indolent in nature with limited metastatic potential. Enhanced renal masses less than 4 cm in size are known as small renal masses (SRMs), and their growth rate (GR) and the possibility of developing metastasis are extremely low. Delayed intervention of SRMs by closed and routine imaging follow-up known as active surveillance (AS) is now an option according to urological guidelines. Radiologists have a key position in AS management of SRMs even unifocal and multifocal (sporadic or associated with genetic syndromes) and also in the follow-up of complex renal cysts by Bosniak cyst classification system. Radiologists play a key role in the AS of both unifocal and multifocal (sporadic or associated with genetic syndromes) SRMs as well as in the follow-up of complex renal cysts using the Bosniak cyst classification system. Indeed, radiologists must determine which patients with SRMs or complex renal cysts can be included in AS, establish the follow-up radiological test algorithm to be used in different scenarios, perform measurements in follow-up tests, and decide when AS should be discontinued. The purpose of this article is to review the indications and management of AS in SRMs, especially focused on specific scenarios, such as complex renal cysts and multifocal renal tumors (sporadic or hereditary). In this work, the authors aimed to provide a thorough review of imaging in the context of active surveillance of renal masses.

Outcomes of synchronous and metachronous bilateral small renal masses (< 4 cm): a population-based cohort study

OBJECTIVES

To report longitudinal outcomes of a population-based cohort of patients diagnosed with bilateral small renal masses from a period of over 11 years.

PATIENTS AND METHODS

Consecutive patients diagnosed with bilateral small renal masses (synchronous or metachronous) of a defined geographical area were recorded in a large database (TUCAN database) between January 2005 and December 2016. Patients had a unique identifier number and followed during this period using an agreed upon protocol. Clinicopathological characteristics and outcomes of bilateral small renal masses on active surveillance were analysed and compared to propensity score-matched sporadic unilateral small renal masses. Data were analysed for renal mass growth rate, rate of intervention and development of metastatic disease and patient survival.

RESULTS

A total of 1060 patients were diagnosed with renal cancer, of which bilateral small renal masses accounted for 70 (6.6%) cases. Synchronous SRMs were observed in 63 patients, whereas metachronous lesions were found in seven patients during the study period. Metachronous lesion mean time to appearance was 62 ± 41 months (range 9-149 months). While most cases were sporadic, four were found to be hereditary. Growth rate of bilateral small renal masses did not differ from that of unilateral sporadic small renal masses. Similarly, there were no differences between the groups for rate of interventions and survival.

CONCLUSIONS

Progression, rate of metastases and survival for patients diagnosed with bilateral small renal masses are similar to those diagnosed with unilateral disease.