Nomogram predicting renal insufficiency after nephroureterectomy for upper tract urothelial carcinoma in the Chinese population: exclusion of ineligible candidates for adjuvant chemotherapy

Development and Validation of a Multivariable Nomogram Predictive of Post-Nephroureterectomy Renal Function

BACKGROUND AND OBJECTIVE

The timing of perioperative nephrotoxic chemotherapy for upper tract urothelial carcinoma (UTUC) remains controversial and strongly depends on predicted platinum eligibility after radical nephroureterectomy (RNU). The study objective was to develop and validate a multivariable nomogram to predict estimated glomerular filtration rate (eGFR) following RNU.

METHODS

This was a multi-institutional retrospective study of patients with UTUC treated with RNU from 2000 to 2020 at seven high-volume referral centers. Use of adjuvant chemotherapy was risk-stratified. Patients were retrospectively randomly allocated 2:1 to discovery and validation cohorts. Discovery data were used to identify independent factors associated with GFR at 1-3 mo after RNU on linear regression, and backward selection was applied for model construction. Accuracy was defined as the percentage of predicted eGFR results within 30% of the corresponding observed eGFR.

KEY FINDINGS AND LIMITATIONS

We included 1100 patients, of whom 733 were in the discovery and 367 were in the validation cohort. Multivariable predictors of postoperative eGFR decline included advanced age (odds ratio [OR] -0.18, 95% confidence interval [CI] -0.28 to -0.08), diabetes (OR -2.38, 95% CI -4.64 to -0.11), and hypertension (OR -2.24, 95% CI -4.16 to -0.32). Factors associated with favorable postoperative eGFR included larger tumor size (OR 10.57, 95% CI 7.4-13.74 for tumors >5 cm vs ≤2 cm) and preoperative eGFR (OR 0.44, 95% CI 0.39-0.49). A composite nomogram predicted postoperative eGFR with good accuracy in both the discovery (80.5%) and validation (78.6%) cohorts. Limitations include exclusion of patients who received neoadjuvant chemotherapy.

CONCLUSIONS

A nomogram that incorporates ubiquitous preoperative clinical variables can predict post-RNU eGFR and was validated with an independent cohort.

PATIENT SUMMARY

We developed a tool that uses patient data to predict eligibility for chemotherapy after surgery to remove the kidney and ureter in patients with cancer in the upper urinary tract.

Upper Tract Urothelial Carcinoma (UTUC) Diagnosis and Risk Stratification: A Comprehensive Review

Diagnosis and risk stratification are cornerstones of therapeutic decisions in the management of patients with upper tract urothelial carcinoma (UTUC). Diagnostic modalities provide data that can be integrated, to provide nomograms and stratification tools to predict survival and adverse outcomes. This study reviews cytology, ureterorenoscopy and the novel tools and techniques used with it (including photodynamic diagnosis, narrow-band imaging, optical coherence tomography, and confocal laser endomicroscopy), and biopsy. Imaging modalities and novel biomarkers are discussed in another article. Patient- and tumor-related prognostic factors, their association with survival indices, and their roles in different scores and predictive tools are discussed. Patient-related factors include age, sex, ethnicity, tobacco consumption, surgical delay, sarcopenia, nutritional status, and several blood-based markers. Tumor-related prognosticators comprise stage, grade, presentation, location, multifocality, size, lymphovascular invasion, surgical margins, lymph node status, mutational landscape, architecture, histologic variants, and tumor-stroma ratio. The accuracy and validation of pre-operative predictive tools, which incorporate various prognosticators to predict the risk of muscle-invasive or non-organ confined disease, and help to decide on the surgery type (radical nephroureterectomy, or kidney-sparing procedures) are also investigated. Post-operative nomograms, which help decide on adjuvant chemotherapy and plan follow-up are explored. Finally, a revision of the current stratification of UTUC patients is endorsed.

Longitudinal GFR trends after neoadjuvant chemotherapy prior to nephroureterectomy for upper tract urothelial carcinoma

PURPOSE

Renal function dictates sequencing and eligibility for definitive therapy in upper tract urothelial carcinoma. We investigated longitudinal glomerular filtration rate (GFR) changes after neoadjuvant chemotherapy (NAC) and nephroureterectomy (RNU).

MATERIALS AND METHODS

Patients treated with ≥3 cycles of chemotherapy prior to RNU for UTUC from 2000 to 2019 were included. GFR was calculated by CKD-Epi before chemotherapy, before RNU, 1 to 3 months, and 12 months post-RNU. Pathologic stage and overall survival were compared in those with stable GFR (+/-10% of baseline) to the rest of the cohort.

RESULTS

One hundred and fifty-two patients received ≥3 cycles of NAC, with 121 (79%) receiving at least 1 cycle of cisplatin. Renal function dropped by mean of 22.3 ml/min/1.73 m2 from the beginning of chemotherapy to 1-year post-surgery. In patients receiving cisplatin, a mean decline of 26.2 ml/min/1.73 m2 was observed vs. 8.8 ml/min/1.73 m2 without cisplatin-based NAC (P < 0.01). GFR after RNU was unchanged between 3 and 12 months postoperatively. At 1 to 3 months after RNU, 19% of patients had GFR<30 ml/min/1.73m2. Improvement in GFR during NAC was associated with invasive final pathologic stage (P = 0.018) and worse overall survival (P = 0.049).

CONCLUSIONS

In patients managed with NAC prior to RNU, renal function stabilizes at 1 to 3 months post-operatively and remains clinically similar for cisplatin or non-cisplatin-based therapy. Improvement in GFR during NAC was associated with higher pathologic stage and poorer survival, especially in those receiving non-cisplatin-based therapy, an observation that requires further investigation.

The Evolution of Clinicopathological Diagnostic Features of Upper Tract Urothelial Carcinoma in China: A Summary of 2561 Cases in the Last 20 Years

Objectives

To summarize the clinicopathological diagnostic features and evolutionary trends of upper tract urothelial carcinoma (UTUC) in China over the past 20 years.

Methods

All patients diagnosed with upper tract urothelial carcinoma in the Peking University First Hospital from 2001 to 2020 were retrospectively collected. Data were divided into two groups (2001-2010 and 2011-2020) according to the date of diagnosis. Statistical analysis was done with the SPSS V22.0. Chi-square analysis and t-test were adopted to analyze depending on the data type. Subgroup analysis based on 5 years was used for visualization to present trends. Both Kaplan-Meier curve and Cox regression were used for univariate and multivariate survival analysis.

Results

The study included 2561 cases diagnosed with upper tract urothelial carcinoma in total. Compared with the first decade (2001-2010), patients of the second decades (2011-2020) had elder mean age (66.65 versus 67.59, years, p=0.025), higher male proportion (43.5% versus 49.0%, p=0.034), lower incidence of renal pelvic tumors (53.4% versus 45.8%, p<0.001) and multifocality (18.6% versus 12.0%, p<0.001), higher incidence of ureteral tumors (52.2% versus 60.9%, p<0.001).In recent ten years, the incidence of muscle-invasive urothelial carcinoma (pT2+) decreased significantly (64.4% versus 54.9%, p<0.001),and the mean size of renal pelvic tumors increased(3.46 versus 3.73, cm, p=0.043). The size of the ureteral tumor, the histopathologic grade showed no significant change. The prognostic analysis based on 709 patients regularly followed at our center revealed that the male gender and G3 histopathological grade were independent risk factors for poorer prognosis in patients with UTUC.

Conclusion

In the past 20 years, the clinicopathological diagnostic features of upper tract urothelial carcinoma in the Chinese population has changed significantly, suggesting an increased risk of a poorer prognosis for UTUC. This trend may be related to updating diagnostic techniques and self-monitoring awareness. However, we need more high-grade, multicenter trials to verify it in the future.

A Preoperative Nomogram to Predict Renal Function Insufficiency for Cisplatin-based Adjuvant Chemotherapy Following Minimally Invasive Radical Nephroureterectomy (ROBUUST Collaborative Group)

BACKGROUND

Postoperative renal function impairment represents a main limitation for delivering adjuvant chemotherapy after radical nephroureterectomy (RNU).

OBJECTIVE

To create a model predicting renal function decline after minimally invasive RNU.

DESIGN, SETTING, AND PARTICIPANTS

A total of 490 patients with nonmetastatic UTUC who underwent minimally invasive RNU were identified from a collaborative database including 17 institutions worldwide (February 2006 to March 2020). Renal function insufficiency for cisplatin-based regimen was defined as estimated glomerular filtration rate (eGFR) <50 ml/min/1.73 m² at 3 mo after RNU. Patients with baseline eGFR >50 ml/min/1.73 m² (n = 361) were geographically divided into a training set (n = 226) and an independent external validation set (n = 135) for further analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Using transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) guidelines, a nomogram to predict postoperative eGFR <50 ml/min/1.73 m² was built based on the coefficients of the least absolute shrinkage and selection operation (LASSO) logistic regression. The discrimination, calibration, and clinical use of the nomogram were investigated.

RESULTS AND LIMITATIONS

The model that incorporated age, body mass index, preoperative eGFR, and hydroureteronephrosis was developed with an area under the curve of 0.771, which was confirmed to be 0.773 in the external validation set. The calibration curve demonstrated good agreement. Besides, the model was converted into a risk score with a cutoff value of 0.583, and the difference between the low- and high-risk groups both in overall death risk (hazard ratio [HR]: 4.59, p < 0.001) and cancer-specific death risk (HR: 5.19, p < 0.001) was statistically significant. The limitation mainly lies in its retrospective design.

CONCLUSIONS

A nomogram incorporating immediately available clinical variables can accurately predict renal insufficiency for cisplatin-based adjuvant chemotherapy after minimally invasive RNU and may serve as a tool facilitating patient selection.

PATIENT SUMMARY

We have developed a model for the prediction of renal function loss after radical nephroureterectomy to facilitate patient selection for perioperative chemotherapy.

Influence of American Society of Anesthesiologists Score on Oncologic Outcomes in Patients With Upper Tract Urothelial Carcinoma After Radical Nephroureterectomy: A Large-Sample Study in Two Institutions

Introduction

As a research team of urologists and an anesthetist, we sought to investigate the prognostic significance of American Society of Anesthesiologists (ASA) score in patients with upper tract urothelial cancer (UTUC) after radical nephroureterectomy (RNU). ASA physical status (ASA-PS) classification not only was found to be associated with increased comorbidities but also independently factors for predicting morbidity and mortality. Accurate risk assessment was being particularly important for patients being considered for surgery.

Methods

Records for 958 patients with UTUC who underwent RNU were reviewed. Clinicopathologic variables, including ASA-PS, were assessed at two institutions. Overall survival (OS), cancer-specific survival (CSS), intravesical recurrence-free survival (IRFS), and metastasis-free survival (MFS) were estimated using the Kaplan–Meier method and Cox regression analyses. We measured the independent predictive value of ASA-PS for mortality by multivariate regression. Association of ASA-PS and clinicopathologic variables was assessed.

Results

The group of patients with ASA = 2/3 had a shorter 5-year OS (67.6% and 49.9%), CSS (72.9% and 58.1%), and MFS (75.1% and 58.5%). The median follow-up time was 39 months. Kaplan–Meier curves showed that the group with ASA = 2/3 had significantly poorer OS, CSS, and MFS. Adjusting for multiple potential confounding factors, multivariate analyses suggested that ASA score was an independent predictor of OS, CSS, and MFS (p = 0.004, p = 0.005, p < 0.001).

Conclusion

Higher ASA scores were independently associated with lower survival rate. This capability, along with its simplicity, makes it a valuable prognostic metric. It should be seriously referenced in UTUC patients being considered for RNU.

Potential of Perfusion Magnetic Resonance Imaging to Predict Residual Renal Function after Radical Nephroureterectomy

INTRODUCTION

The diffusion-weighted imaging (DWI) technique with intravoxel incoherent motion model enables the estimation of capillary blood volume as a perfusion-related parameter- (PP-) value. Therefore, the PP-value of the kidney theoretically reflects renal capillary blood volume. We analyzed the usefulness of the PP-value in estimating postoperative renal function in upper-tract urothelial carcinoma (UTUC) patients.

METHODS

Forty-eight consecutive patients who underwent magnetic resonance imaging before radical nephroureterectomy from 2011 to 2018 were analyzed. A PP-map displaying PP-values on a pixel-by-pixel basis was created from DWI signals (b-values of 0, 500, and 1,000 s/mm2). Two readers independently analyzed the renal PP-value. DWI-based split renal function (SRF) of the intact kidney was calculated by splitting serum Cr-based preoperative estimated glomerular filtration rates (eGFRs). The predictive accuracy of the method was evaluated using renography as the reference standard.

RESULTS

Interobserver analysis revealed an excellent correlation value of 0.97. The SRF value showed a good linear correlation with the observed postoperative eGFR (r = 0.76, p < 0.001). The predictive accuracy of the DWI-based method was similar to that of the nuclear-based method.

CONCLUSION

This DWI-based evaluation of capillary blood volume provides a noninvasive tool for predicting the postoperative renal function, thereby facilitating the management of UTUC patients.

Development and validation of a PD-L1/PD-1/CD8 axis-based classifier to predict cancer survival of upper tract urothelial carcinoma after radical nephroureterectomy

The expression status of programmed cell death-ligand 1/programmed cell death 1 (PD-L1/PD-1) and the infiltration of CD8⁺ T cells in tumor tissues are considered to be related to immunotherapy efficacy and patient prognosis. The purpose of this study is to clarify the prognostic value of the PD-L1/PD-1/CD8 axis, and to develop and validate a comprehensive scoring system based on multiple immune variables to predict cancer survival of upper tract urothelial carcinoma (UTUC) after radical nephroureterectomy (RNU). The immunohistochemical method was used to detect the expression of PD-L1, PD-1, and CD8 in cancer tissues of UTUC patients after RNU. Then, an immunoscore was constructed using the least absolute shrinkage and selection operator (LASSO) Cox regression model in the training cohort (n = 120), and it was verified in the validation cohort (n = 54). We found that infiltration of PD-L1⁺ immune cells (ICs), stromal PD-1⁺ tumor-infiltrating lymphocytes (TILs), and intratumoral CD8⁺ TILs was associated with poor overall survival (OS). The immunoscore based on the three immune variables further divided the patients into low- and high-risk groups, and there was a significant difference in the survival rate. A nomogram was constructed by combining tumor-node-metastasis (TNM) stage and immunoscore, and the area under the curve of the receiver-operating characteristic (ROC) (0.78) for predicting 5-year mortality was better than that of the TNM stage (0.70) and immunoscore (0.76). Our results show that the PD-L1/PD-1/CD8 axis-based classifier have potential clinical application to predict cancer survival of UTUC patients after RNU.

Prevalence, clinicopathological features, and prognosis in upper tract urinary carcinoma patients with severe preoperative chronic kidney disease

BACKGROUND

Studies regarding the prevalence and factors associated with severe pre-operative chronic kidney disease (CKD) in upper tract urinary carcinoma (UTUC) patients were rare due to the low prevalence of UTUC. We conducted the present study to investigate the prevalence, clinicopathological features, and prognosis in UTUC patients with severe preoperative CKD.

METHODS

The study included 731 patients with UTUC treated with radical nephroureterectomy (RNU) in a large Chinese center. Estimated glomerular filtration rate (eGFR) was calculated by re-expressed Modification of Diet in Renal Disease (MDRD) formulas for the Chinese population. Severe preoperative CKD was defined as CKD stage 4-5 (eGFR <30 mL/min). Relationships of CKD stage 4-5 with clinicopathological characteristics, overall survival (OS), cancer-specific survival (CSS), contralateral recurrence-free survival and intravesical recurrence (IVR)-free survival were analyzed.

RESULTS

A total of 73 (10.0%) patients presented severe preoperative CKD in this cohort. Multivariate logistic analysis indicated that female gender (OR =1.791; 95% CI: 1.018-3.150; P=0.043), lower BMI (OR =0.452; 95% CI: 0.262-0.778; P=0.004), concomitant bladder tumor (OR =2.944; 95% CI: 1.360-6.373; P=0.006), lower pathological T stage (OR =0.578; 95% CI: 0.339-0.984; P=0.043), tumor necrosis (OR =2.764; 95% CI: 1.411-5.416; P=0.003), and exposure of aristolochic acid (AA) (OR =3.115; 95% CI: 1.536-6.316; P=0.002) were significantly related to severe CKD. Multivariate Cox's regression analysis showed that severe preoperative CKD was significantly associated with worse OS (HR =1.840; 95% CI: 1.150-2.944; P=0.011) and worse contralateral recurrence-free survival (HR =3.269; 95% CI: 1.607-6.650; P=0.001), while no statistical difference in terms of CSS or IVR-free survival were noticed.

CONCLUSIONS

Female gender, lower BMI, concomitant bladder tumor, lower pathological T stage, exposure of AA, and tumor necrosis were independently associated with severe preoperative CKD in UTUC patients. UTUC patients with severe preoperative CKD possess worse OS and higher possibility of contralateral upper urinary tract recurrence.

Developing a prediction model for disease-free survival from upper urinary tract urothelial carcinoma in the Korean population

Background

In this study, we aimed to propose a validated prediction model for disease‐free survival (DFS) after radical nephroureterectomy (RNU) in a Korean population with upper urinary tract urothelial carcinoma (UTUC).

Methods

We performed a retrospective review of 1561 cases of UTUC who underwent either open RNU (ONU, n = 906) or laparoscopic RNU (LNU, n = 615) from five tertiary Korean institutions between January 2000 and December 2012. Data were used to develop a prediction model using the Cox proportional hazards model. Prognostic factors were selected using the backward variable selection method. The prediction model performance was investigated using Harrell's concordance index (C‐index) and Hosmer‐Lemeshow type 2 statistics. Internal validation was performed using a bootstrap approach, and the National Cancer Center data set (n = 128) was used for external validation.

Results

A best‐fitting prediction model with seven significant factors was developed. The C‐index and two Hosmer‐Lemeshow type statistics of the prediction model were 0.785 (95% CI, 0.755‐0.815), 4.810 (P = 0.8506), and 5.285 (P = 0.8088). The optimism‐corrected estimate through the internal validation was 0.774 (95% CI, 0.744‐0.804) and the optimism‐corrected calibration curve was close to the ideal line with mean absolute error = 0.012. In external validation, the discrimination was 0.657 (95% CI, 0.560‐0.755) and the two calibration statistics were 0.790 (P = 0.9397) and 3.103 (P = 0.5408), respectively.

Conclusion

A validated prediction model based on a large Korean RNU cohort was developed with acceptable performance to estimate DFS in patients with UTUC.

Impact of the ASA Physical Status Score on Adjuvant Chemotherapy Eligibility and Survival of Upper Tract Urothelial Carcinoma Patients: a Multicenter Study

The aim of the present multi-institutional study was to assess the influence of the American Society of Anesthesiologists Physical Status (ASA-PS) classification on adjuvant chemotherapy eligibility and survival in a multi-institutional cohort of patients treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). We retrospectively reviewed data from 416 patients who underwent RNU for UTUC at four Korean institutions between 2001 and 2013. The ASA-PS classification was obtained from the anesthesia chart. Locally advanced UTUC was defined as ≥ pT3 and/or pN1 disease. The influence of ASA-PS score on survival was evaluated by Kaplan-Meier analyses and a multivariate Cox regression model. Patients with a higher ASA-PS class were less likely to be eligible for adjuvant chemotherapy in locally advanced UTUC (P = 0.016). Kaplan-Meier estimates showed that the high-risk ASA-PS group has a poorer overallsurvival (OS) and cancer-specific survival (CSS) compared to low risk ASA-PS groups in both the total and locally advanced UTUC cohorts. Based on multivariate Cox regression analysis, the high-risk ASA-PS category was an independent predictor for overall mortality (OM) (hazard ratio [HR], 1.919; 95% confidence interval [CI], 1.017-3.619; P = 0.044) and cancer-specific mortality (CSM) (HR, 2.120; 95% CI, 1.023-4.394; P = 0.043). In conclusion, high-risk ASA-PS score was independently associated with a lower survival rate in patients with UTUC after RNU. However, the influence of ASA-PS classification on survival was limited to locally advanced UTUC. The lower eligibility of patients in the high-risk ASA category for adjuvant chemotherapy may contribute to the lower survival rate in this group.

Upper urinary tract disease: what we know today and unmet needs

Purpose

Upper tract urothelial carcinoma (UTUC) is a rare and poorly investigated disease. Intense collaborative efforts have increased our knowledge and improved the management of the disease. The objective of this review was to discuss recent advances and unmet needs in UTUC.

Methods

A non-systematic Medline/PubMed literature search was performed on UTUC using the terms “upper tract urothelial carcinoma” with different combinations of keywords. Original articles, reviews and editorials in English language were selected based on their clinical relevance.

Results

UTUC is a disease with specific epidemiologic and risk factors different to urothelial carcinoma of the bladder (UCB). Similarly to UCB, smoking increases the risk of UTUC and worsens its prognosis, whereas aristolochic acid (AA) exposure and mismatch repair genes abnormality are UTUC specific risk factors. A growing understanding of biological pathways involved in the tumorigenesis of UTUC has led to the identification of promising prognostic/predictive biomarkers. Risk stratification of UTUC is difficult due to limitations in staging and grading. Modern imaging and endoscopy have improved clinical decision-making, and allowed kidney-sparing management and surveillance in favorable-risk tumors. In high-risk tumors, radical nephroureterectomy (RNU) remains the standard. Complete removal of the intramural ureter is necessary with inferiority of endoscopic management. Post-RNU intravesical instillation has been shown to decrease bladder cancer recurrence rates. While the role of neoadjuvant cisplatin based combination chemotherapy and lymphadenectomy are not clearly established, the body of evidence suggests a survival benefit to these. There is currently no evidence for adjuvant chemotherapy (AC) in UTUC.

Conclusions

Despite growing interest and understanding of UTUC, its management remains challenging, requiring further high quality multicenter collaborations. Accurate risk estimation is necessary to avoid unnecessary RNUs while advances in technology are still required for optimal kidney-sparing approaches.