Comparison of rates and risk factors for development of osteoporosis and fractures after radical or partial nephrectomy

Impact of worsening surgically induced chronic kidney disease (CKD-S) in preoperative CKD-naïve patients on survival in renal cell carcinoma

OBJECTIVES

To evaluate effects of worsening surgically induced chronic kidney disease (CKD-S) on oncological and non-oncological survival outcomes in renal cell carcinoma (RCC).

PATIENTS AND METHODS

We performed a retrospective analysis of patients who underwent partial (PN) or radical nephrectomy (RN) and were free of preoperative CKD (estimated glomerular filtration rate [eGFR] ≥60 mL/min/1.73 m² ). Patients were stratified by CKD stage at last follow-up: no CKD-S (eGFR ≥60 mL/min/1.73 m² ), de novo CKD-S 3a (eGFR 45-59 mL/min/1.73 m² ), CKD-S 3b (eGFR <45 and ≥30 mL/min/1.73 m² ) and CKD-S 4 (eGFR <30 and ≥15 mL/min/1.73 m² ). The primary outcome was all-cause mortality (ACM). Secondary outcomes included non-cancer mortality (NCM), cancer-specific mortality (CSM) and de novo CKD-S Stage 3/4. Multivariable analysis (MVA) was utilised to identify risk factors for outcomes. Kaplan-Meier analysis (KMA) was utilised to evaluate overall (OS), non-cancer (NCS), and cancer-specific survival with respect to CKD-S categories.

RESULTS

We analysed 3239 patients. The mean preoperative and last-follow-up eGFRs were 87.4 and 69.5 mL/min/1.73 m² , respectively. On last follow-up, 57.9% (n = 1876) had no CKD-S, 18.7% (n = 606) had CKD-S 3a, 15.1% (n = 489) had CKD-S 3b and 8.3% (n = 268) had CKD-S 4. On MVA, de novo CKD-S 3b and 4 were independently associated with ACM (hazard ratios [HRs] 1.3-2.1, P = 0.003-0.001) and NCM (HRs 1.5-2.8, P = 0.021-0.001), but not CSM (P = 0.219-0.909); de novo CKD-S 3a was not predictive for any mortality outcomes (P = 0.102-0.81). RN was independently associated with CKD-S 3-4 (HRs 1.78-1.99, P < 0.001-0.035). Comparing no CKD-S, CKD-S 3a, CKD-S 3b and CKD-S 4, KMA demonstrated worsening outcomes with progressive CKD-S stage: 5-year OS 84% vs 78% vs 71% vs 60% (P < 0.001) and 5-year NCS 93% vs 87% vs 83% vs 72% (P < 0.001).

CONCLUSION

Development of CKD-S Stage 3b and 4, but not 3a, was associated with worsened ACM and NCM. The decision to proceed with nephron preservation via PN should be individualised based on oncological risk and risk of functional decline to CKD-S 3b or 4, and not CKD-S 3a.

Partial Nephrectomy Versus Radical Nephrectomy for Endophytic Renal Tumors: Comparison of Operative, Functional, and Oncological Outcomes by Propensity Score Matching Analysis

Purpose

The study aimed to compare operative, functional, and oncological outcomes between partial nephrectomy (PN) and radical nephrectomy (RN) for entophytic renal tumors (ERTs) by propensity score matching (PSM) analysis.

Methods

A total of 228 patients with ERTs who underwent PN or RN between August 2014 and December 2021 were assessed. A PSM in a 1:1 ratio was conducted to balance the differences between groups. Perioperative characteristics, renal functional, and oncological outcomes were compared between groups. Univariate and multivariate logistic and Cox proportional hazard regression analyses were used to determine the predictors of functional and survival outcomes.

Results

After PSM, 136 cases were matched to the PN group (n = 68) and the RN group (n = 68). Patients who underwent RN had shorter OT, less EBL, and lower high-grade complications (all p <0.05) relative to those who underwent PN. However, better perseveration of renal function was observed in the PN group, which was reflected in 48-h postoperative AKI (44.1% vs. 70.6%, p = 0.002), 1-year postoperative 90% eGFR preservation (45.6% vs. 22.1%, p = 0.004), and new-onset CKD Stage ≥III at last follow-up (2.9% vs. 29.4%, p <0.001). RN was the independent factor of short-term (OR, 2.812; 95% CI, 1.369–5.778; p = 0.005) and long-term renal function decline (OR, 10.242; 95% CI, 2.175–48.240; p = 0.003). Furthermore, PN resulted in a better OS and similar PFS and CSS as compared to RN (p = 0.042, 0.15, and 0.21, respectively). RN (OR, 7.361; 95% CI, 1.143–47.423; p = 0.036) and pT3 stage (OR, 4.241; 95% CI, 1.079–16.664; p = 0.039) were independent predictors of overall mortality.

Conclusion

Among patients with ERTs, although the PN group showed a higher incidence of high-grade complications than RN, when technically feasible and with experienced surgeons, PN is recommended for better preservation of renal function, longer OS, and similar oncological outcomes.

Retroperitoneal laparoscopic partial versus radical nephrectomy for large (≥ 4 cm) and anatomically complex renal tumors: A propensity score matching study

INTRODUCTION

To assess the safety and efficiency of retroperitoneal laparoscopic partial nephrectomy (RLPN) and retroperitoneal laparoscopic radical nephrectomy (RLRN) for large (≥4 cm) renal tumors with a RENAL nephrometry score ≥7.

MATERIALS AND METHODS

We retrospectively identified and analyzed the data of 254 patients who underwent RLPN or RLRN for large (≥4 cm) and anatomically complex renal tumors between 2008 and 2017. Propensity score matching (PSM) (1:1) method was conducted to adjust for preoperative clinical characteristics. Preoperative, renal functional, and oncological outcomes were compared.

RESULTS

Finally, no significant differences in the baseline characteristics existed between the two groups after PSM. Within the well-balanced matched cohort, longer operating time (OT) and higher estimated blood loss (EBL) were found in RLPN group (p = 0.015 and p = 0.019, respectively), and RLPN trended to protect renal function better at a higher risk of low-grade complications (-10.9 vs -16.8 ml/min, p = 0.001; 23.0% vs 10.8%, p = 0.048, respectively). The patients in the RLPN group had a better overall survival (OS) than those in RLRN group, but cancer-specific survival and progression-free survival didn't differ significantly between the two groups.

CONCLUSION

For patients with large (≥4 cm) and anatomically complex renal tumors, RLPN by highly experienced hands has an evident tendency to a better protection of renal function and a longer OS without waiving oncological control in comparison with RLRN, but at the expense of longer OT, a higher EBL and a higher risk of low-grade complications.

Management of bone complications in patients with genitourinary malignancies

Skeletal metastases are common in genitourinary malignancies-including prostate cancer, renal cell carcinoma, and urothelial cancer-and portend significant morbidity and poor prognosis. The presence of skeletal metastases can result in decreased quality of life and increased morbidity. Strategies can be employed to prevent bone-related complications including lifestyle modifications and dietary supplementation. Additionally, pharmacologic agents exist to prevent bone loss and may be appropriate for patients at high risk of fragility-related or skeletal complications, such as pathologic fracture related to bone metastases. Finally, advancement in effective systemic treatments, particularly novel hormone-targeted agents and immunotherapies, may limit the morbidity of advanced disease and delay the onset of skeletal-related complications.

A Return to the Days of Radical Nephrectomy as the "Gold Standard" for Localized Renal Cell Carcinoma? Not So Fast

Recent work by Gershman and colleagues adds to collective data favoring partial nephrectomy to optimize functional preservation while maintaining oncological equipoise in the management of T1 renal cancer, and should not be over-interpreted as an endorsement to preferentially perform radical nephrectomy.

Predictors of Long-Term Survival after Renal Cancer Surgery

PURPOSE

Renal cancer surgery can adversely impact long-term function and survival. We evaluated predictors of chronic kidney disease 5 years and nonrenal cancer mortality 10 years after renal cancer surgery.

MATERIALS AND METHODS

We analyzed the records of 4,283 patients who underwent renal cancer surgery from 1997 to 2008. Radical and partial nephrectomy were performed in 46% and 54% of patients, respectively. Cumulative probability ordinal modeling was used to predict chronic kidney disease status 5 years after surgery and multivariable logistic regression was used to predict nonrenal cancer mortality at 10 years. Relevant patient, tumor and functional covariates were incorporated, including the preoperative glomerular filtration rate (A), the new baseline glomerular filtration rate after surgery (B) and the glomerular filtration rate loss related to surgery (C), that is C = A - B. In contrast, partial or radical nephrectomy was not used in the models due to concerns about strong selection bias associated with the choice of procedure.

RESULTS

Multivariable modeling established the preoperative glomerular filtration rate and the glomerular filtration rate loss related to surgery as the most important predictors of the development of chronic kidney disease (Spearman ρ = 0.78). Age, gender and race had secondary roles. Significant predictors of 10-year nonrenal cancer mortality were the preoperative glomerular filtration rate, the new baseline glomerular filtration rate, age, diabetes and heart disease (all p <0.05). Multivariable modeling established age and the preoperative glomerular filtration rate as the most important predictors of 10-year nonrenal cancer mortality (c-index 0.71) while the glomerular filtration rate loss related to surgery only changed absolute mortality estimates 1% to 3%.

CONCLUSIONS

Glomerular filtration rate loss related to renal cancer surgery, whether due to partial or radical nephrectomy, influences the risk of chronic kidney disease but it may have less impact on survival. In contrast, age and the preoperative glomerular filtration rate, which reflects general health status, are more robust predictors of nonrenal cancer mortality, at least in patients with good preoperative function or mild chronic kidney disease.

Partial nephrectomy versus radical nephrectomy for clinical localised renal masses

BACKGROUND

Partial nephrectomy and radical nephrectomy are the relevant surgical therapy options for localised renal cell carcinoma. However, debate regarding the effects of these surgical approaches continues and it is important to identify and summarise high-quality studies to make surgical treatment recommendations.

OBJECTIVES

To assess the effects of partial nephrectomy compared with radical nephrectomy for clinically localised renal cell carcinoma.

SEARCH METHODS

We searched CENTRAL, MEDLINE, PubMed, Embase, Web of Science, BIOSIS, LILACS, Scopus, two trial registries and abstracts from three major conferences to 24 February 2017, together with reference lists; and contacted selected experts in the field.

SELECTION CRITERIA

We included a randomised controlled trial comparing partial and radical nephrectomy for participants with small renal masses.

DATA COLLECTION AND ANALYSIS

One review author screened all of the titles and abstracts; only citations that were clearly irrelevant were excluded at this stage. Next, two review authors independently assessed full-text reports, identified relevant studies, evaluated the eligibility of the studies for inclusion, assessed trial quality and extracted data. The update of the literature search was performed by two independent review authors. We used Review Manager 5 for data synthesis and data analyses.

MAIN RESULTS

We identified one randomised controlled trial including 541 participants that compared partial nephrectomy to radical nephrectomy. The median follow-up was 9.3 years.Based on low quality evidence, we found that time-to-death of any cause was decreased using partial nephrectomy (HR 1.50, 95% CI 1.03 to 2.18). This corresponds to 79 more deaths (5 more to 173 more) per 1000. Also based on low quality evidence, we found no difference in serious adverse events (RR 2.04, 95% CI 0.19 to 22.34). Findings are consistent with 4 more surgery-related deaths (3 fewer to 78 more) per 1000.Based on low quality evidence, we found no difference in time-to-recurrence (HR 1.37, 95% CI 0.58 to 3.24). This corresponds to 12 more recurrences (14 fewer to 70 more) per 1000. Due to the nature of reporting, we were unable to analyse overall rates for immediate and long-term adverse events. We found no evidence on haemodialysis or quality of life.Reasons for downgrading related to study limitations (lack of blinding, cross-over), imprecision and indirectness (a substantial proportion of patients were ultimately found not to have a malignant tumour). Based on the finding of a single trial, we were unable to conduct any subgroup or sensitivity analyses.

AUTHORS' CONCLUSIONS

Partial nephrectomy may be associated with a decreased time-to-death of any cause. With regards to surgery-related mortality, cancer-specific survival and time-to-recurrence, partial nephrectomy appears to result in little to no difference.

The effect of nephrectomy on Klotho, FGF-23 and bone metabolism

Background

Increased concentration of fibroblast growth factor 23 (FGF-23) and decreased levels of soluble Klotho (sKL) are linked to negative clinical outcomes among patients with chronic kidney disease and acute kidney injury. Therefore, it is reasonable to hypothesize that GFR reduction caused by nephrectomy might alter mineral metabolism and induces adverse consequences. Whether nephrectomy due to urological indications causes derangements in FGF-23 and sKL has not been studied. The aim of the study was to evaluate the effect of acute GFR decline due to unilateral nephrectomy on bone metabolism, FGF-23 and sKL levels.

Methods

This is a prospective, single-centre observational study of patients undergoing nephrectomy due to urological indications. Levels of C-terminal FGF-23 (c-FGF-23), sKL and bone turnover markers [β-crosslaps (CTX), bone-specific alkaline phosphatase (bALP) and tartrate-resistant acid phosphatase 5b (TRAP 5b)] were measured before and after surgery (5 ± 2 days).

Results

Twenty-nine patients were studied (14 females, age 63.0 ± 11.6, eGFR 87.3 ± 19.2 ml/min/1.73 m²). After surgery, eGFR significantly declined (p < 0.0001). Nephrectomy significantly decreased sKL level [709.8 (599.9–831.2) vs. 583.0 (411.7–752.6) pg/ml, p < 0.001] and did not change c-FGF-23 concentration [70.5 (49.8–103.3) vs. 77.1 (60.5–109.1) RU/ml, p = 0.9]. Simultaneously, alterations in bone turnover markers were observed. Serum concentration of CTX increased [0.49 (0.4–0.64) vs. 0.59 (0.46–0.85) ng/ml, p = 0.001], while bALP and TRAP 5b decreased [23.6 (18.8–31.4) vs. 17.9 (15.0–22.0) U/l, p < 0.0001 and 3.3 (3.0–3.7) vs. 2.8 (2.3–3.2) U/l, p < 0.001, respectively].

Conclusions

Nephrectomy among patients with preserved renal function before surgery does not increase c-FGF-23 but reduces sKL. Moreover, nephrectomy results in derangements in bone turnover markers in short-term follow-up. These changes may participate in pathogenesis of bone disease after nephrectomy.

Collaborative Review of Risk Benefit Trade-offs Between Partial and Radical Nephrectomy in the Management of Anatomically Complex Renal Masses

BACKGROUND

While partial nephrectomy (PN) is the recommended treatment for many small renal masses, anatomically complex tumors necessitate a clear understanding of the potential risks and benefits of PN and radical nephrectomy (RN).

OBJECTIVE

To critically review the comparative effectiveness evidence of PN versus RN; to describe key trade-offs involved in this treatment decision; and to highlight gaps in the current literature.

EVIDENCE ACQUISITION

A collaborative critical review of the medical literature was conducted.

EVIDENCE SYNTHESIS

Patients who undergo PN for an anatomically complex or large mass may be exposed to perioperative and potential oncologic risks that could be avoided if RN were performed, while patients who undergo RN may forgo long-term benefits of renal preservation. Decision-making regarding the optimal treatment with PN or RN among patients with anatomically complex or large renal mass is highly nuanced and must balance the risks and benefits of each approach. Currently, high-quality evidence on comparative effectiveness is sparse. Retrospective comparisons are plagued by selection biases, while the one existing prospective randomized trial, albeit imperfect, suggests that nephron-sparing surgery may not benefit all patients.

CONCLUSIONS

For anatomically complex tumors, PN preserves renal parenchyma but may expose patients to higher perioperative risks than RN. The risks and benefits of each surgical approach must be better objectified for identification of patients most suitable for complex PN. A prospective randomized trial is warranted and would help in directing patient counseling.

PATIENT SUMMARY

Treatment decisions for complex renal masses require shared decision-making regarding the risk trade-offs between partial and radical nephrectomy.

Bone Density Is Directly Associated With Glomerular Filtration and Metabolic Acidosis but Do Not Predict Fragility Fractures in Men With Moderate Chronic Kidney Disease

Hyperparathyroidism, vitamin D deficiency, increased fibroblast growth factor-23 (FGF-23), and metabolic acidosis promote bone fragility in chronic kidney disease (CKD). Although useful in predicting fracture risk in the general population, the role of dual-energy X-ray absorptiometry (DXA) in CKD remains uncertain. This cross-sectional study included 51 men aged 50-75 yr with moderate CKD. The stage 4 CKD patients had higher levels of parathyroid hormone (p<0.001), FGF-23 (p=0.029), and lowest 25-hydroxyvitamin D (p=0.016), bicarbonate (p<0.001), total femur (p=0.003), and femoral neck (p=0.011) T-scores compared with stage 3 CKD patients. Total femur and femoral neck T-scores were directly correlated with serum bicarbonate (p=0.003, r=0.447 and p=0.005, r=0.427, respectively) and estimated glomerular filtration rate (p=0.024, r=0.325 and p=0.003, r=0.313, respectively) but were not significantly associated with parathyroid hormone, 25-hydroxyvitamin D, or FGF-23. Only 3.9% of the participants had osteoporosis on DXA scan, whereas 31.4% reported a low-impact fracture. Our data point to a pivotal role of metabolic acidosis for bone impairment and to the inadequacy of DXA to evaluate bone fragility in CKD patients.

Emerging surgical treatments for renal cell carcinoma

Treatment of renal cell carcinoma has evolved considerably over the last few years. While total nephrectomy is necessary at times, nephron-sparing surgery, with a goal of renal function preservation, should always be considered. Although open partial nephrectomy is considered the gold standard approach for nephron-sparing surgery, laparoscopic- or robotic-assisted techniques allow urologists to perform renal surgery less invasively, with excellent long-term oncological outcomes. Cryotherapy and radiofrequency ablation are less invasive management approaches for carefully selected patients with small renal masses. Active surveillance should be considered in elderly or patients who are unfit for surgery. Ultimately, the method chosen for management of a renal mass is an informed decision made by the physician and patient.

Association of serum bicarbonate with bone fractures in hemodialysis patients: the mineral and bone disorder outcomes study for Japanese CKD stage 5D patients (MBD-5D)

BACKGROUND/AIMS

Bone fracture is often complicated in hemodialysis (HD) patients. Metabolic acidosis is related to bone disease and muscle wasting, but it is not known whether acid-base disturbance is associated with the risk of bone fractures. The aim of this study was to clarify the association of serum bicarbonate level with bone fracture in HD patients.

METHODS

Using a subcohort of the Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D), 890 prevalent HD patients (age: 62 years old, male: 62.8%, duration of dialysis: 8.3 years) with secondary hyperparathyroidism were studied. After measuring predialysis serum bicarbonate at a 2-day interdialytic interval, we prospectively followed them every 3 months, and examined the occurrence of any type of bone fracture or hospitalization due to fracture over a 3-year observation period.

RESULTS

Seventy-four bone fractures and 47 hospitalizations due to fracture were observed during the follow-up period. HD patients with serum bicarbonate <20 mmol/l had a 1.93 (95% CI 1.01-3.71)-fold higher risk for all-cause fractures than those with serum bicarbonate of 20.0-21.9 mmol/l. A higher bicarbonate level (≥22 mmol/l) was also related to an increased risk of bone fracture. A restricted cubic regression spline disclosed that the higher or the lower than 21.0 mmol/l of serum bicarbonate, the greater the risk for bone fracture.

CONCLUSION

Both a lower level and a higher level of predialysis bicarbonate concentration were associated with risk of bone fracture in HD patients with secondary hyperparathyroidism.

Is radical nephrectomy a legitimate therapeutic option in patients with renal masses amenable to nephron-sparing surgery?

The decision to perform a radical nephrectomy (RN) or a partial nephrectomy (PN), not unlike most decisions in clinical practice, ultimately hinges on the balance of risk. Do the higher risks of a more complex surgery (PN) justify the theoretical benefits of kidney tissue preservation? Data suggest that for patients with an anatomically complex renal mass and a normal contralateral kidney, for whom additional surgical intensity may be risky, such as the elderly and comorbid, RN presents a robust treatment option. Nevertheless, PN, especially for small and anatomically simple renal masses in young patients without comorbidities should remain the surgical reference standard, as preservation of renal tissue can serve as an 'insurance policy' not only against future renal functional decline, but also against the possibility of tumour development in the contralateral kidney. In the present review, we outline the ongoing debate between the role of RN and PN in treatment of the enhancing renal mass.

Impact of renal surgery for cortical neoplasms on lipid metabolism

OBJECTIVE

To examine the incidence of and risk factors for development of hyperlipidaemia in patients undergoing radical nephrectomy (RN) or partial nephrectomy (PN) for renal cortical neoplasms, as hyperlipidaemia is a major source of morbidity in chronic kidney disease (CKD).

PATIENTS AND METHODS

We conducted a two-centre retrospective analysis of 905 patients (mean age 57.5 years, mean follow-up 78 months), who underwent RN (n = 610) or PN (n = 295) between July 1987 and June 2007. Demographics, preoperative and postoperative hyperlipidaemia were recorded. De novo hyperlipidaemia was defined as that ocurring ≥6 months after surgery in cases where laboratory values met National Cholesterol Education Program Adult Treatment Panel III definitions. The Kaplan-Meier method was used to assess freedom from de novo hyperlipidaemia. Multivariable analysis was conducted to determine the risk factors for de novo hyperlipidaemia.

RESULTS

There were no significant differences with respect to demographics, preoperative glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) (P = 0.123) and hyperlipidaemia (P = 0.144). Tumour size (cm) was significantly larger in the RN group vs the PN group (7.0 vs 3.7; P < 0.001). Significantly greater postoperative GFR <60 mL/min/1.73 m(2) was noted in the RN group (45.7 vs 18%, P < 0.001). Significantly, more de novo hyperlipidaemia developed in the RN group than in the PN group (23 vs 6.4%; P < 0.001). The mean time to development of hyperlipidaemia was longer for PN than for RN (54 vs 44 months; P = 0.03). Five-year freedom from de novo hyperlipidaemia probability was 76% for RN vs 96% for PN (P < 0.001). Multivariable analysis showed that RN (odds ratio [OR] 2.93; P = 0.0107), preoperative GFR <60 mL/min/1.73 m(2) (OR 1.98; P = 0.037) and postoperative GFR <60 mL/min/1.73 m(2) (OR 7.89; P < 0.001) were factors associated with hyperlipidaemia development.

CONCLUSION

Patients who underwent RN had a significantly higher incidence of and shorter time to development of de novo hyperlipidaemia. RN and pre- and postoperative eGFR <60 mL/min/1.73 m(2) were associated with development of hyperlipidaemia. Further follow-up and prospective investigation are necessary to confirm these findings.

Incidence and risk factors of chronic kidney disease in korean patients with t1a renal cell carcinoma before and after radical or partial nephrectomy

OBJECTIVE

The aim of the study was to investigate the incidence of chronic kidney disease in patients with T1a renal cell carcinoma both before and after partial or radical nephrectomy, and to assess risk factors for chronic kidney disease.

METHODS

From January 2001 to December 2011, 1928 patients with a single renal mass ≤4 cm undergoing partial nephrectomy or radical nephrectomy with the existence of a normal contralateral kidney were retrospectively reviewed for the evaluation of preoperative chronic kidney disease, and reviewed only 1676 patients for the postoperative chronic kidney disease. The estimated glomerular filtration rates were used to define chronic kidney disease <60 ml/min/1.73 m(2) by the Modification of Diet in Renal Disease equation. Demographics and clinicopathological parameters were evaluated to determine the risk factors with the development of chronic kidney disease both before and after surgery.

RESULTS

Chronic kidney disease was found preoperatively in 10.0% (n = 192) of patients; 16.1% (n = 269) of patients developed chronic kidney disease postoperatively, including 102 (6.1%) chronic kidney disease patients >65 years of age. Between the non-chronic kidney disease and chronic kidney disease patients, male gender (odds ratio 3.55 vs. 3.78, respectively) and diagnostic age (odds ratio 1.04 vs. 1.05) were significantly distinctive common risk factors for chronic kidney disease both before and after surgery (P < 0.002). In addition, hypertension (odds ratio 0.46), serum albumin (odds ratio 0.23) and calcium (odds ratio 2.06) were significant as preoperative risk factors (P < 0.015), and preoperative serum creatinine (odds ratio 1.90) and surgical type (partial nephrectomy or radical nephrectomy; odds ratio 11.89) were significant as postoperative risk factors (P < 0.030).

CONCLUSIONS

Old, male hypertensive patients with a small renal mass would be better candidates for partial nephrectomy to prevent postoperative chronic kidney disease.

Image based feasibility of renal sparing surgery for very low risk unilateral Wilms tumors: a report from the Children's Oncology Group

PURPOSE

Nephrectomy with lymph node sampling is the recommended treatment for children with unilateral Wilms tumor under the Children's Oncology Group protocols. Using radiological assessment, we determined the feasibility of performing partial nephrectomy in a select group of patients with very low risk unilateral Wilms tumor.

MATERIALS AND METHODS

We reviewed imaging studies of 60 patients with a mean age of less than 2 years with very low risk unilateral Wilms tumor (mean weight less than 550 gm) to assess the feasibility of partial nephrectomy. We evaluated percentage of salvageable parenchyma, tumor location and anatomical features preventing a nephron sparing approach.

RESULTS

A linear relationship exists between tumor weight and computerized tomography estimated tumor volume. Mean tumor weight in the study population was 315 gm. Partial nephrectomy was deemed feasible in only 5 of 60 patients (8%).

CONCLUSIONS

When considering a select population with very low risk unilateral Wilms tumor (lower volume tumor), only a small percentage of nonpretreated patients are candidates for nephron sparing surgery.

Oncology: the role of partial nephrectomy in Wilms tumor

Wilms tumor represents the most common pediatric renal malignancy and the fourth most common childhood cancer overall. Overall survival from Wilms tumor has increased to over 90 % secondary to multidisciplinary therapy and multi-institutional cooperative group trials. Recent therapeutic focus has shifted to reduction in treatment morbidity and renal preservation while maintaining the high survival rates. Partial nephrectomy is an integral component of the multimodal treatment protocols for Wilms tumor patients with bilateral disease, solitary kidney, or predisposing syndromes. Recent consideration has been given to utilization of nephron sparing surgery (NSS) in carefully selected patients with nonsyndromic unilateral Wilms tumor. While long-term, prospective data in this subgroup of patients is not yet available, case series demonstrate comparable oncologic outcomes after partial versus radical nephrectomy. The relative rarity of Wilms tumor, especially those amenable to upfront partial nephrectomy, presents a challenge to conducting controlled trials.