The difficulty in selecting patients for cytoreductive nephrectomy: An evaluation of previously described predictive models

Role of Surgery in Metastatic Renal Cell Carcinoma

Surgery has historically been the mainstay of treatment for metastatic renal cell carcinoma (mRCC), but recent clinical trials demonstrated that contemporary systemic therapies alone are non-inferior to cytoreductive nephrectomy (CN). Thus, the current role of surgery is not precisely defined. CN remains an appropriate upfront treatment for the palliation of severe symptoms, select cases of metastatic non-clear cell renal cell carcinoma, for consolidation following systemic therapy, and in the setting of oligometastatic disease. Metastasectomy is ideally utilized to achieve a disease-free state when there is minimal morbidity associated with surgery. Given the heterogenous nature of mRCC, the decision for systemic therapy and surgery should be made through a multidisciplinary approach tailored to each individual patient.

Are markers of survival associated with perioperative outcomes for tumor thrombectomy patients?

INTRODUCTION

Despite modern advances in surgical and perioperative technologies, management of renal cell carcinoma (RCC) with tumor thrombus (TT) is a morbid procedure that necessitates careful patient selection. It is not known whether established prognostic models for metastatic RCC are suitable prognostic tools for more immediate perioperative outcomes in patients with RCC with TT. We evaluated if established risk models for cytoreductive nephrectomy, as a potential extension of their purpose-built use, are associated with immediate perioperative outcomes in patients undergoing nephrectomy and tumor thrombectomy.

METHODS

Perioperative outcomes of patients who underwent radical nephrectomy and tumor thrombectomy for RCC were compared to presences of established predictors of long-term outcomes from prior risk models individually and as stratified by risk grouping (International Metastatic Renal-Cell Carcinoma Database Consortium [IMDC], Memorial Sloan Kettering Cancer Center [MSKCC], M.D. Anderson Cancer Center [MDACC], and Moffitt Cancer Center [MCC]). Wilcoxon rank-sum test or the Kruskal-Wallis test compared continuous variables and the chi-square test or Fisher's exact test compared categorical variables.

RESULTS

Fifty-five patients were analyzed with 17 (30.9%) being cytoreductive. Eighteen (32.7%) patients had a level III or higher TT. Individually, preoperative variables were inconsistently associated with perioperative outcomes. Poorer risk patients per the IMDC model had more major postoperative complications (Clavien-Dindo grade≥3, P = 0.008). For the MSKCC model, poorer risk patients had increased intraoperative estimated blood loss (EBL), longer length of stay (LOS), more major postoperative complications, and more likely to discharge to a rehabilitation facility (P < 0.05). Less favorable risk patients per MDACC model had increased LOS (P = 0.038). Poorer risk patients per the MCC model had increased EBL, LOS, major postoperative complications, and 30-day hospital readmissions (P < 0.05).

CONCLUSION

Overall, cytoreductive risks models were heterogeneously associated with perioperative outcomes in patients undergoing nephrectomy and tumor thrombectomy. Of available models, the MCC model is associated with more perioperative outcomes including EBL, LOS, major postoperative complications, and readmissions within 30 days when compared to the IMDC, MSKCC, and MDACC models.

Selection and evaluation of preoperative systemic inflammatory response biomarkers model prior to cytoreductive nephrectomy using a machine-learning approach

INTRODUCTION

This study aimed to determine the prognostic value of a panel of SIR-biomarkers, relative to standard clinicopathological variables, to improve mRCC patient selection for cytoreductive nephrectomy (CN).

MATERIAL AND METHODS

A panel of preoperative SIR-biomarkers, including the albumin-globulin ratio (AGR), De Ritis ratio (DRR), and systemic immune-inflammation index (SII), was assessed in 613 patients treated with CN for mRCC. Patients were randomly divided into training and testing cohorts (65/35%). A machine learning-based variable selection approach (LASSO regression) was used for the fitting of the most informative, yet parsimonious multivariable models with respect to prognosis of cancer-specific survival (CSS). The discriminatory ability of the model was quantified using the C-index. After validation and calibration of the model, a nomogram was created, and decision curve analysis (DCA) was used to evaluate the clinical net benefit.

RESULTS

SIR-biomarkers were selected by the machine-learning process to be of high discriminatory power during the fitting of the model. Low AGR remained significantly associated with CSS in both training (HR 1.40, 95% CI 1.07-1.82, p = 0.01) and testing (HR 1.78, 95% CI 1.26-2.51, p = 0.01) cohorts. High levels of SII (HR 1.51, 95% CI 1.10-2.08, p = 0.01) and DRR (HR 1.41, 95% CI 1.01-1.96, p = 0.04) were associated with CSS only in the testing cohort. The exclusion of the SIR-biomarkers for the prognosis of CSS did not result in a significant decrease in C-index (- 0.9%) for the training cohort, while the exclusion of SIR-biomarkers led to a reduction in C-index in the testing cohort (- 5.8%). However, SIR-biomarkers only marginally increased the discriminatory ability of the respective model in comparison to the standard model.

CONCLUSION

Despite the high discriminatory ability during the fitting of the model with machine-learning approach, the panel of readily available blood-based SIR-biomarkers failed to add a clinical benefit beyond the standard model.

Evolving biological associations of upfront cytoreductive nephrectomy in metastatic renal cell carcinoma

BACKGROUND

Systemic responses to cytoreductive nephrectomy (CN) in the management of metastatic renal cell carcinoma (mRCC) are variable and difficult to anticipate. The authors aimed to determine the association of CN with modifiable International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk factors and oncological outcomes.

METHODS

Consecutive patients with mRCC referred for potential CN (2009-2019) were reviewed. The primary outcome was overall survival (OS); variables of interest included undergoing CN and the baseline number of modifiable IMDC risk factors (anemia, hypercalcemia, neutrophilia, thrombocytosis, and reduced performance status). For operative cases, the authors evaluated the effects of IMDC risk factor dynamics, measured 6 weeks and 6 months after CN, on OS and postoperative treatment disposition.

RESULTS

Of 245 treatment-naive patients with mRCC referred for CN, 177 (72%) proceeded to surgery. The CN cases had fewer modifiable IMDC risk factors (P = .003), including none in 71 of 177 patients (40.1%); fewer metastases (P = .011); and higher proportions of clear cell histology (P = .012). In a multivariable analysis, surgical selection, number of IMDC risk factors, metastatic focality, and histology were associated with OS. Total risk factors changed for 53.8% and 57.2% of the patients from the preoperative period to 6 weeks and 6 months after CN, respectively. Adjusted for preoperative IMDC risk scores, an increase in IMDC risk factors at 6 weeks and 6 months was associated with adverse OS (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.13-2.19; P = .007; HR, 2.52; 95% CI, 1.74-3.65; P < .001).

CONCLUSIONS

IMDC risk factors are dynamic clinical variables that can improve after upfront CN in select patients, and this suggests a systemic benefit of cytoreduction, which may confer clinically meaningful prognostic implications.

Dissecting Outcomes: Should Cytoreductive Nephrectomy Be Performed for Patients With Metastatic Renal Cell Carcinoma With Sarcomatoid Dedifferentiation?

Background

It is highly contested whether cytoreductive nephrectomy for treating advanced renal cell carcinoma (RCC) with sarcomatoid features (sRCC) benefits overall survival. Patients with sRCC are known to have a poor prognosis, and these tumors have a more aggressive biology than those without sarcomatoid features.

Methods

Patients with clear cell RCC or non–clear cell RCC underwent cytoreductive nephrectomy in efforts to improve overall survival (OS). Patients were stratified by presence or absence of histologic sarcomatoid features within tumor samples.

Results

Of 167 patients who underwent cytoreductive nephrectomy, 127 had clear cell RCC, of whom 14 had sarcomatoid features, and 40 had non–clear cell RCC, of whom 13 had sarcomatoid features. Median age of the cohort was 62 years (range, 56.5–69 years). The cohort included 119 male (71.3%) and 48 (28.7%) female patients. Among all patients with advanced RCC, having sRCC had a significantly worse OS after cytoreductive nephrectomy (30 vs 8 months; hazard ratio [HR], 2.88; P <0.0001). Additionally, favorable-risk patients had significantly longer OS compared to intermediate- or poor-risk patients (56 vs 30 vs 10 months; HR, 0.21; P =0.00016). For patients with clear cell RCC, having sRCC conferred a significantly poorer survival (30 vs 9 months; HR, 2.82; P=0.0035). Patients with non–clear cell sRCC also had significantly worse outcomes compared to patients whose tumors did not have sarcomatoid features (30 vs 6.5 months; HR, 3; P =0.009). When patients with sRCC were stratified by whether there was >10% or ≤10% sarcomatoid features present within the sample, there was no significant difference in OS (8 vs 8.5 months; P =0.32).

Conclusions

Sarcomatoid features within tumor histology confer significantly poor prognosis. Patients with sRCC, regardless of clear cell vs non–clear cell histology, have significantly shorter OS. Even among patients with 10% or less sarcomatoid features, there was no OS benefit to cytoreductive nephrectomy. Based on our findings, there appears to be a limited to no role of cytoreductive nephrectomy if sRCC is identified on pretreatment biopsy. The role of radiomics and pre-operative biopsies may confer significant benefit in this patient population.

Survival following cytoreductive nephrectomy: a comparison of existing prognostic models

OBJECTIVE

To validate models currently used to predict metastatic renal cell carcinoma (mRCC) outcomes in a cohort of patients undergoing cytoreductive nephrectomy (CN).

PATIENTS AND METHODS

A total of 10 RCC prognostic models (International Metastatic RCC Database Consortium [IMDC]; Memorial Sloan Kettering Cancer Center [MSKCC]; Culp; Leibovich; University of California at Los Angeles Integrated Staging System [UISS]; Stage, Size, Grade, and Necrosis [SSIGN]; Yaycioglu; Karakiewicz; Cindolo; and Margulis) were chosen based on clinical relevance and use in clinical trial design. Model validation was performed using patients who underwent CN at a single institution between 2005 and 2017, and model discrimination (ability to select patients at risk of death) was assessed. Concordance indices (c-index) were calculated and compared with originally published c-indices.

RESULTS

A total of 515 CN patients were stratified according to the prognostic models. A total of 387 (75%) died over the study period, with estimated 3-year survival of 46.1% (95% confidence interval [CI] 41.6-50.4%). All models' discriminatory capacity underperformed when compared to the originally published c-indices. The c-indices ranged from 0.53 (95% CI 0.50-0.56) for the Cindolo model to 0.61 (95% CI 0.58-0.64) for the Leibovich model. The MSKCC and IMDC models performed poorly with c-indices of 0.55 and 0.56, respectively.

CONCLUSION

Currently used prognostic models have limited discriminatory capacity when applied to a modern cohort of patients undergoing CN. They are inadequate for risk stratification and randomisation in prospective clinical trials of untreated patients with mRCC. Caution should be used when using these models for clinical decision making.

The Association Between Small Primary Tumor Size and Prognosis in Metastatic Renal Cell Carcinoma: Insights from Two Independent Cohorts of Patients Who Underwent Cytoreductive Nephrectomy

BACKGROUND

One of the main challenges in the management of renal cell carcinoma (RCC) is risk-stratifying patients who present with metastatic disease. Tumor size is an important predictor of survival in the localized setting; however, this feature has not been explored fully in patients presenting with M1 RCC.

OBJECTIVE

To assess the impact of tumor size on survival in patients with metastatic RCC who underwent cytoreductive nephrectomy (CN).

DESIGN, SETTING, AND PARTICIPANTS

We queried the Memorial Sloan Kettering (MSK) nephrectomy database for patients who presented with M1 disease and underwent CN between 1989 and 2016 (n=304). Primary tumor size was obtained from pathology reports. Data from the International Metastatic Database Consortium (IMDC) were used for validation purposes (n=778).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall survival (OS) estimates were computed using the Kaplan-Meier method. Cox regressions were used to test the association between tumor size and OS in univariate and multivariable analyses. Tumors ≤4cm were compared with larger masses. Secondary analyses were performed to assess the robustness of these findings.

RESULTS AND LIMITATIONS

Clear cell tumors ≤4cm were significantly associated with improved OS in both the MSK (hazard ratio [HR]: 0.35, 0.17-0.72, p= 0.004) and IMDC (HR 0.54, 0.36-0.83, p= 0.004) cohorts. The association was observed even after adjusting for known prognostic factors (HR 0.40, 0.14-1.14, p= 0.09 and HR: 0.54, 0.33-0.90, p= 0.02 in the MSK and IMDC cohorts, respectively). Limitations of this study include the absence of patients who were considered poor surgical candidates as well as potential selection bias.

CONCLUSIONS

The primary tumor size ≤4cm was independently associated with improved OS in patients with metastatic clear cell RCC who underwent CN. Additionally, the association between primary size and survival was found to be nonlinear. These findings suggest that there is a group of small metastatic RCCs that can convey a better overall prognosis. The potential role of primary tumor size when risk stratifying patients with M1 RCC should be explored further to determine its utility during clinical decision making.

PATIENT SUMMARY

We evaluated the impact of small tumor size on prognosis in patients with metastatic kidney cancer who undergo removal of the primary tumor. Very small masses (≤4cm) were associated with better prognosis in patients with clear cell tumors.

The evolving role of cytoreductive nephrectomy: incorporating genomics of metastatic renal cell carcinoma into treatment decisions

PURPOSE OF REVIEW

Recent publications evaluating cytoreductive nephrectomy in the era of targeted therapy emphasize the importance of patient selection. We reviewed the predictive role of genetic alterations in patients with metastatic renal cell carcinoma (mRCC) undergoing cytoreductive nephrectomy.

RECENT FINDINGS

Studies evaluating the association between genetic alterations and outcomes following systemic treatment for mRCC include mainly patients after cytoreductive nephrectomy. Expression of proangiogenic genes, single nucleotide polymorphisms involving genes of the vascular-endothelial growth factor (VEGF) pathway and somatic mutations of chromatin remodeling genes were associated with response to VEGF-targeted therapy. Outcomes following treatment with mammalian target of rapamycin (mTOR) inhibitors were initially associated with mTOR/TSC1/TSC2 mutations; however, subsequent studies did not validate these findings but rather found an association between loss of PTEN expression and PBRM1 mutations and improved outcomes. Loss of PBRM1 was initially linked to response to immunotherapy; however, larger studies question this association and showed high expression of T-effector gene signature predicted improved outcome. Primary tumors with low intratumor heterogeneity but elevated somatic copy-number alterations were associated with rapid progression at multiple sites.

SUMMARY

Genetic alterations may help select patients for cytoreductive nephrectomy and optimize timing of treatment. Intratumor heterogeneity and genetic discordance between primary and metastatic tumors may limit clinical applicability. Future studies should evaluate approaches to overcome these limitations.

Preoperative evaluation of the degree of liver fibrosis based on matter-element analysis using serological indicators in patients with hepatocellular carcinoma

Evaluation of the degree of liver fibrosis is an important basis for the clinical diagnosis and treatment of patients with hepatocellular carcinoma (HCC). It is meaningful to make a preoperative evaluation with non-invasive methods. In the current study, 12 commonly used preoperative serological indicators from 161 HCC patients with different degree of liver fibrosis were collected retrospectively, and 8 of the indicators (ALB, PA, TBil, INR, AST, GGT, ALP, and PT) were ultimately used in matter-element analysis to create a formula. The relationship between those results and the histological sub-classification of the Laennec liver fibrosis scoring system was analyzed. The calculated value of R from this formula will indicate the differing degree of liver fibrosis in a patient: i) the value of 0.802 ≤ R < 1 indicates the early stage of liver cirrhosis, which corresponds to Laennec stages 0-3; ii) the value of 0.752 ≤ R < 0.802 indicates the mild stage of liver cirrhosis, which corresponds to Laennec stage 4A; iii) the value of 0.698 ≤ R < 0.752 indicates the moderate stage of liver cirrhosis, which corresponds to Laennec stage 4B; and iv) the value of 0.444 ≤ R < 0.698 indicates the severe stage of liver cirrhosis, which corresponds to Laennec stage 4C. The hope is that this formula for preoperative evaluation of the degree of liver fibrosis using non-invasive methods would be useful in the clinical diagnosis and treatment of patients with HCC in the future.

The use of cytoreductive nephrectomy in patients with renal cell carcinoma

INTRODUCTION

The systemic options for managing metastatic renal cell carcinoma (mRCC) have expanded considerably over the past decade. Initially limited to cytokines, clinicians may now choose from several classes of targeted therapies and, most recently, immune checkpoint inhibitors. Areas covered: In this review, we discuss the role and timing of cytoreductive nephrectomy (CN) and its evolution starting with cytokines, and then alongside the emergence of targeted therapy and novel immunotherapy with immune checkpoint inhibitors. Patient selection remains the most critical determinant in offering CN, and the anticipated survival benefits of CN must be weighed against the surgical morbidity and potential delay to receipt of systemic therapies. Expert opinion: Proper patient selection is key for decision-making in mRCC. Prospective data is urgently needed to define the role of CN in the contemporary immunotherapy era, with greater personalization of prognostic models.

The Value of Neutrophil to Lymphocyte Ratio in Patients Undergoing Cytoreductive Nephrectomy with Thrombectomy

BACKGROUND

The neutrophil-lymphocyte ratio (NLR) is an established signature of inflammation used for evaluating renal cell carcinoma (RCC).

OBJECTIVE

To determine the utility of NLR and its relationship with known risk factors associated with poor survival in patients with metastatic RCC and tumor thrombus undergoing cytoreductive nephrectomy (CN).

DESIGN, SETTING, AND PARTICIPANTS

Prognostic variables were reviewed for patients undergoing CN with thrombectomy between 2000 and 2014 from six different institutions. Patients were stratified for NLR >4.0 based on cut point analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier curves compared overall survival of the total cohort and established risk models (Memorial Sloan Kettering Cancer Center [MSKCC], International Metastatic Renal-Cell Carcinoma Database Consortium [IMDC], and M.D. Anderson Cancer Center [MDACC]) stratified by NLR. Multivariable Cox regression determined predictors of overall survival. Receiver operator characteristic curves tested the predictive accuracy of survival ≥12 mo, and area under the curve (AUC) was compared between models.

RESULTS AND LIMITATIONS

In total, 332 patients were identified. Patients with NLR ≤4.0 had longer median survival (24.7 vs 15.2 mo, p=0.004). NLR >4.0 distinguished patients with significantly shorter survival for non-poor-risk groups defined by MSKCC, IMDC, and MDACC criteria. Systemic symptoms, low hemoglobin, elevated lactate dehydrogenase, retroperitoneal adenopathy, level IV thrombus, elevated absolute neutrophil count, and NLR >4 were independent predictors of decreased survival (p<0.05). These factors had higher predictive accuracy for survival at 12 mo (AUC=0.755) than MKSCC, IMDC, and MSKCC models.

CONCLUSIONS

NLR >4.0 independently predicts poor survival and further distinguishes established risk model survival curves. We identified seven preoperative risk factors related to poor survival for patients with metastatic RCC with tumor thrombus undergoing CN.

PATIENT SUMMARY

The neutrophil-lymphocyte ratio and six additional preoperative variables can be used to better council patients regarding survival after surgery for metastatic renal cell carcinoma with tumor thrombus.

External validation of a predictive model of survival after cytoreductive nephrectomy for metastatic renal cell carcinoma

INTRODUCTION

Recent trials have emphasized the importance of a precise patient selection for cytoreductive nephrectomy (CN). In 2013, a nomogram was developed for pre- and postoperative prediction of the probability of death (PoD) after CN in patients with metastatic renal cell carcinoma. To date, the single-institutional nomogram which included mostly patients from the cytokine era has not been externally validated. Our objective is to validate the predictive model in contemporary patients in the targeted therapy era.

METHODS

Multi-institutional European and North American data from patients who underwent CN between 2006 and 2013 were used for external validation. Variables evaluated included preoperative serum albumin and lactate dehydrogenase levels, intraoperative blood transfusions (yes/no) and postoperative pathologic stage (primary tumour and nodes). In addition, patient characteristics and MSKCC risk factors were collected. Using the original calibration indices and quantiles of the distribution of predictions, Kaplan-Meier estimates and calibration plots of observed versus predicted PoD were calculated. For the preoperative model a decision curve analysis (DCA) was performed.

RESULTS

Of 1108 patients [median OS of 27 months (95% CI 24.6-29.4)], 536 and 469 patients had full data for the validation of the pre- and postoperative models, respectively. The AUC for the pre- and postoperative model was 0.68 (95% CI 0.62-0.74) and 0.73 (95% CI 0.68-0.78), respectively. In the DCA the preoperative model performs well within threshold survival probabilities of 20-50%. Most important limitation was the retrospective collection of this external validation dataset.

CONCLUSIONS

In this external validation, the pre- and postoperative nomograms predicting PoD following CN were well calibrated. Although performance of the preoperative nomogram was lower than in the internal validation, it retains the ability to predict early death after CN.

Surgical Management of Advanced and Metastatic Renal Cell Carcinoma: A Multidisciplinary Approach

The past decade has seen a rapid proliferation in the number and types of systemic therapies available for renal cell carcinoma. However, surgery remains an integral component of the therapeutic armamentarium for advanced and metastatic kidney cancer. Cytoreductive surgery followed by adjuvant cytokine-based immunotherapy (predominantly high-dose interleukin 2) has largely given way to systemic-targeted therapies. Metastasectomy also has a role in carefully selected patients. Additionally, neoadjuvant systemic therapy may increase the feasibility of resecting the primary tumor, which may be beneficial for patients with locally advanced or metastatic disease. Several prospective trials examining the role of adjuvant therapy are underway. Lastly, the first immune checkpoint inhibitor was approved for metastatic renal cell carcinoma (mRCC) in 2015, providing a new treatment mechanism and new opportunities for combining systemic therapy with surgery. This review discusses current and historical literature regarding the surgical management of patients with advanced and mRCC and explores approaches for optimizing patient selection.