The role of nephrologists in the management of small renal masses

The Detrimental Effect of Metabolic Syndrome on Long-term Renal Function in Patients Undergoing Elective Partial Nephrectomy for Small Renal Masses

Background and objective

Metabolic syndrome (MetS) is a clinical condition associated with higher rates of overall and cardiovascular mortality. There is scarce evidence regarding the impact of MetS on surgical and functional outcomes for patients undergoing partial nephrectomy (PN) for clinically localized small renal masses (SRMs).

Methods

We analyzed data from a prospectively maintained institutional database for 690 patients with cT1a renal cancer undergoing PN between 2000 and 2023 at a tertiary referral center. MetS was defined according to international guidelines. Cumulative incidence curves were used to estimate the 5-yr risk of stage IIIB-V chronic kidney disease (CKD) stage and other-cause mortality (OCM). Multivariable regression models were used to analyze the impact of MetS on the risk of complications, acute kidney injury (AKI), stage IIIB-V CKD, and OCM.

Key findings and limitations

Overall, 10% of the PN cohort had MetS. The MetS group was older (median age 70 yr, interquartile range [IQR] 65-74 vs 61 yr, IQR 50-69; p < 0.001) and had worse preoperative kidney function (median estimated glomerular filtration rate 65 [IQR 62-81] vs 88 [IQR 69-98] ml/min/1.73 m2; p < 0.001) than the group without MetS. The MetS group had higher incidence of complications (odds ratio [OR] 1.81, 95% confidence interval [CI] 1.05-3.08; p = 0.03) and postoperative AKI (OR 3.17, 95% CI 1.54-6.41; p = 0.001). The 5-yr risk of stage IIIB-V CKD (45% vs 7.2%; hazard ratio [HR] 2.34, 95% CI 1.27-4.30; p = 0.006) and OCM (14% vs 3.5%; HR 3.00, 95% CI 1.06-8.55; p = 0.039) were also higher in the MetS group. The main limitations are the extended accrual time and unmeasured confounders that could potentially affect outcomes.

Conclusions and clinical implications

Patients with MetS had worse postoperative, functional, and survival outcomes after SRM surgery in comparison to patients without MetS. Multidisciplinary care could help in reducing the preoperative metabolic burden in these patients. Further research should explore if alternative approaches (eg, surveillance or focal therapy) could minimize postoperative comorbidities and protect long-term renal function in this population.

Patient summary

Patients with a condition called metabolic syndrome who have part of their kidney removed for small kidney tumors are at higher risk of complications and long-term kidney issues. Patient care from a multidisciplinary team could help in reducing the metabolic burden before surgery. Further research is needed to explore if less invasive treatment options could reduce these risks.

Birt-Hogg-Dubé Syndrome and Hereditary Leiomyomatosis and Renal Cell Carcinoma Syndrome: An Effective Multidisciplinary Approach to Hereditary Renal Cancer Predisposing Syndromes

Aim

We aimed to describe and analyse clinical features, characteristics, and adherence to surveillance guidelines in an Australian Birt-Hogg-Dubé syndrome (BHD) and hereditary leiomyomatosis and renal cell cancer (HLRCC) cohort.

Methods

All identified patients with a diagnosis of BHD or HLRCC at RBWH 01/01/2014-01/09/2019 were included (HREC/17/QRBW/276). All patients were initially assessed and counselled by a clinical geneticist and then referred to an adult nephrologist. Baseline and incidental clinical variables were extracted and analysed.

Results

Fifty-seven patients were identified (28 BHD, 29 HLRCC) with a median age of 47 years. The median and cumulative follow-up were 1 and 99 years, respectively. Baseline renal MRI occurred in 40/57 patients, and 33/57 had regular MRI as per the national guidelines (eviQ). Of 18/57 without baseline imaging, nine were yet to have imaging, seven were lost follow-up, and two patients had logistic difficulties. RCC was diagnosed in 11/57 patients: two of 28 with BHD were diagnosed with RCC aged 73 and 77, both prior to commencement of surveillance. Nine of 29 patients with HLRCC were diagnosed with RCC (one of 29 during surveillance at 47 years of age) and eight of 29 prior to commencement of surveillance (11-55 years). Amongst BHD patients, cutaneous fibrofolliculomas were noted in 15 patients, lung cysts were detected in seven patients, spontaneous pneumothoraces in five patients, and parotid oncocytoma in two of 28. Amongst those with HLRCC, cutaneous leiomyomas were noted in 19/29, cutaneous leiomyosarcoma diagnosed in one of 29, and uterine fibroids in 13 female patients.

Conclusion

Evidence-based RCC screening in BHD and HLRCC cohort is feasible and able to identify incidental renal lesions. Multidisciplinary patient management enables expedited genetic counselling, diagnosis, longitudinal screening, and RCC management. The success of this clinical model warrants consideration of undertaking longitudinal screening of BHD and HLRCC patients by nephrologists.

Effects of metabolic syndrome on renal function after radical nephrectomy in patients with renal cell carcinoma

PURPOSE

Nephrectomy, partial or radical, remains the standard treatment for renal cell carcinoma (RCC). However, increased risk of chronic kidney disease (CKD) must still be considered. This study aimed to evaluate the effects of concomitant metabolic syndrome (MetS) on renal function in patients with RCC after radical nephrectomy.

METHODS

Medical records of 310 patients who underwent radical nephrectomy for clear-cell RCC at 900th Hospital of the Joint Logistics Support Force, PLA from December 2012 to January 2017 were reviewed retrospectively. Estimated glomerular filtration rate (eGFR) and CKD stages were calculated at one week preoperative as baseline and then at postoperative 1 week, 3 months, 12 months and 24 months. MetS patients were identified and enrolled in the MetS group (n = 31), and a non-MetS group was selected by propensity score matching (n = 31). Non-neoplastic renal parenchyma specimens taken at least 2 cm from edge of tumor were evaluated.

RESULTS

Baseline characteristics between the two groups were comparable. At 24 months postoperative, mean eGFR levels of the MetS group were significantly lower than those in the non-MetS group (62.7 vs. 73.3 ml/min/1.73 m²; p = 0.004). CKD stages were still more severe in the MetS group than those in the non-MetS group (p = 0.006). The proportions of global sclerosis, tubular atrophy and interstitial fibrosis were all significantly more prevalent in MetS patients, compared to non-MetS patients (all p < 0.05).

CONCLUSION

In RCC patients with MetS, the possibility of declining eGFR and CKD progression must be considered after radical nephrectomy. Routine monitoring of renal function must be emphasized.

End-Stage Kidney Disease following Surgical Management of Kidney Cancer

BACKGROUND AND OBJECTIVES

We investigated the incidence of ESKD after surgical management of kidney cancer in the Australian state of Queensland, and described patterns in the initiation of kidney replacement therapy resulting from kidney cancer across Australia.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All newly diagnosed cases of kidney cancer in the Australian state of Queensland between January of 2009 and December of 2014 were ascertained through the Queensland Cancer Registry. There were 2739 patients included in our analysis. Patients who developed ESKD were identified using international classification of disease-10-coded hospital administrative data. Incidence rate and 3-year cumulative incidence were calculated, and multivariable Cox proportional hazards models were used to identify factors associated with ESKD. Additional descriptive analysis was undertaken of Australian population data.

RESULTS

The incidence rate of ESKD in all patients was 4.9 (95% confidence interval [95% CI], 3.9 to 6.2) per 1000 patient-years. The 3-year cumulative incidence was 1.7%, 1.9%, and 1.0% for all patients, and patients managed with radical or partial nephrectomy, respectively. Apart from preoperative kidney disease, exposures associated with increased ESKD risk were age≥65 years (adjusted hazard ratio [aHR], 2.0; 95% CI, 1.2 to 3.2), male sex (aHR, 2.3; 95% CI, 1.3 to 4.3), preoperative diabetes (aHR, 1.8; 95% CI, 1.0 to 3.3), American Society of Anesthesiologists classification ≥3 (aHR, 4.0; 95% CI, 2.2 to 7.4), socioeconomic disadvantage (aHR, 1.6; 95% CI, 0.9 to 2.7), and postoperative length of hospitalization ≥6 days (aHR, 2.1; 95% CI, 1.4 to 3.0). Australia-wide trends indicate that the rate of kidney replacement therapy after oncologic nephrectomy doubled between 1995 and 2015, from 0.3 to 0.6 per 100,000 per year.

CONCLUSIONS

In Queensland between 2009 and 2014, one in 53 patients managed with radical nephrectomy and one in 100 patients managed with partial nephrectomy developed ESKD within 3 years of surgery.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_09_28_CJASNPodcast_18_1_.mp3.