Bladder cancer in renal allograft recipients: risk factors and outcomes

Management of bladder cancer in kidney transplant recipients: A narrative review

Background

Bladder cancer in the setting of previous a kidney transplant (KT) is challenging to manage due to complex medical and surgical considerations.

Objective

To provide a comprehensive evaluation of the scope of management of bladder cancer in KT patients, and describe the controversies surrounding these management options.

Methods

A systematic review of studies reporting management of KT patients with bladder cancer and involving ≥3 patients was performed. A narrative review was also performed for various aspects of management such as pathophysiology, surgical considerations, intravesical therapy, immunosuppression and oncological surveillance.

Results

Bladder cancer incidence in KT recipients is 2.8-4.1 times higher than the general population, and there is a notable association with aristolochic acid nephropathy as well as BK virus oncogenesis. Regarding surgical treatment, transurethral resection is preferred for non-muscle invasive tumors, and intravesical BCG for intermediate- and high-risk patients appears to be underutilized despite its safety and associated reduction in recurrence. Radical cystectomy with limited pelvic lymph node dissection, urinary diversion, and consideration of bilateral nephroureterectomy appears to be the safest method of oncological control in muscle-invasive tumors. A switch in immunosuppressive regimens to mTOR inhibitors may be considered in lieu of its antitumor effects. Routine surveillance in KT patients with risk factors for bladder cancer is challenging and may be warranted especially in the Asian population which has a higher rate of urothelial malignancy.

Conclusions

This review provides a thorough summary of management strategies for bladder cancer in the setting of previous KT.

Genitourinary malignancies in kidney transplant recipients

Advances in immunosuppressive therapy and postoperative management have greatly improved the graft and patient survival rates after kidney transplantation; however, the incidence of post-transplant malignant tumors is increasing. Post-renal transplantation malignant tumors are associated with renal failure, immunosuppression, and viral infections. Moreover, the risk of developing cancer is higher in kidney transplant recipients than in the general population, and the tendency to develop cancer is affected by the background and environment of each patient. Recently, cancer after kidney transplantation has become the leading cause of death in Japan. Owing to the aggressive nature and poor prognosis of genitourinary malignancies, it is crucial to understand their epidemiology, risk factors, and best practices in kidney transplant recipients. This review has a special emphasis on the epidemiology, risk factors, and treatment protocols of genitourinary malignancies in kidney transplant recipients to enhance our understanding of the appropriate management strategies. Optimal immunosuppressive therapy and cancer management for these patients remain controversial, but adherence to the general guidelines is recommended.

Systematic review on oncologic outcomes on adjuvant endovesical treatment for non-muscle invasive bladder cancer in patients with solid organ transplant

PURPOSE

Urothelial carcinoma has a higher incidence in renal transplanted patients according to several registries (relative risk × 3), and the global prognosis is inferior to the general population. The potential impact of immunosuppressive therapy on the feasibility, efficacy, and complications of endovesical treatment, especially Bacillus Calmette-Guerin, has a low level of evidence. We performed a systematic review that aimed to assess the morbidity and oncological outcomes of adjuvant endovesical treatment in solid organ transplanted patients.

METHODS

Medline was searched up to December 2021 for all relevant publications reporting oncologic outcomes of endovesical treatment in solid organ transplanted patients with NMIBC. Data were synthesized in light of methodological and clinical heterogeneity.

RESULTS

Twenty-three retrospective studies enrolling 238 patients were included: 206 (96%) kidney transplants, 5 (2%) liver transplants, and 2 (1%) heart transplants. Concerning staging: 25% were pTa, 62% were pT1, and 22% were CIS. 140/238 (59%) patients did not receive adjuvant treatment, 50/238 (21%) received mitomycin C, 4/238 (2%) received epirubicin, and 46/238 (19%) received BCG. Disease-free survival reached 35% with TURBT only vs. 47% with endovesical treatment (Chi-square test p = 0.08 OR 1.2 [0.98-1.53]). The complication rate of endovesical treatment was 12% and was all minor (Clavien-Dindo I).

CONCLUSION

In solid organ transplanted patients under immunosuppressive treatment, both endovesical chemotherapy and BCG are safe, but the level of evidence concerning efficacy in comparison with the general population is low. According to these results, adjuvant treatment should be proposed for NMIC in transplanted patients as in the general population.

Urological Cancers and Kidney Transplantation: a Literature Review

PURPOSE OF REVIEW

The aim of this review is to provide an overview of epidemiology, risk factors, and treatment of urological malignancies in renal transplant recipients (RTR).

RECENT FINDINGS

Although optimal immunosuppressive therapy and cancer management in these patients remain controversial, adherence to general guidelines is recommended. Kidney transplantation is recognized as the standard of care for the treatment of end-stage renal disease (ESRD) as it offers prolonged survival and better quality of life. In the last decades, survival of RTRs has increased as a result of improved immunosuppressive therapy; nonetheless, the risk of developing cancer is higher among RTRs compared to the general population. Urological malignancies are the second most common after hematological cancer and often have more aggressive behavior and poor prognosis.

Risk factors, management, and survival of bladder cancer after kidney transplantation

INTRODUCTION AND OBJECTIVES

Kidney transplantation is associated with an increased risk of bladder cancer; however guidelines have not been established on the management of bladder cancer after kidney transplantation.

MATERIALS AND METHODS

A systematic literature review using PubMed was performed in accordance with the PRISMA statement to identify studies concerning the prevalence and survival of bladder cancer after kidney transplantation. The risk factors and management of bladder cancer after kidney transplantation were also reviewed and discussed.

RESULTS

A total of 41 studies, published between 1996 and 2018, reporting primary data on bladder cancer after kidney transplantation were identified. Marked heterogeneity in bladder cancer prevalence, time to diagnosis, non-muscle invasive/muscle-invasive bladder cancer prevalence, and survival was noted. Four studies, published between 2003 and 2017, reporting primary data on bladder cancer treated with Bacillus Calmette-Guérin (BCG) after kidney transplantation were identified. Disease-free survival, cancer-specific survival, and overall survival were similar between BCG studies (75-100%).

CONCLUSIONS

Carcinogen exposure that led to ESRD, BKV, HPV, immunosuppressive agents, and the immunosuppressed state likely contribute to the increased risk of bladder cancer after renal transplantation. Non-muscle invasive disease should be treated with transurethral resection. BCG can be safely used in transplant recipients and likely improves the disease course. Muscle-invasive disease should be treated with radical cystectomy, with special consideration to the dissection and urinary diversion choice. Chemotherapy and immune checkpoint inhibitors can be safely used in regionally advanced bladder cancer with potential benefit. mTOR inhibitors may reduce the risk of developing bladder cancer, and immunosuppression medications should be reduced if malignancy develops.

Risk factors, management, and survival of bladder cancer after kidney transplantation

INTRODUCTION AND OBJECTIVES

Kidney transplantation is associated with an increased risk of bladder cancer; however guidelines have not been established on the management of bladder cancer after kidney transplantation.

MATERIALS AND METHODS

A systematic literature review using PubMed was performed in accordance with the PRISMA statement to identify studies concerning the prevalence and survival of bladder cancer after kidney transplantation. The risk factors and management of bladder cancer after kidney transplantation were also reviewed and discussed.

RESULTS

A total of 41 studies, published between 1996 and 2018, reporting primary data on bladder cancer after kidney transplantation were identified. Marked heterogeneity in bladder cancer prevalence, time to diagnosis, non-muscle invasive/muscle-invasive bladder cancer prevalence, and survival was noted. Four studies, published between 2003 and 2017, reporting primary data on bladder cancer treated with Bacillus Calmette-Guérin (BCG) after kidney transplantation were identified. Disease-free survival, cancer-specific survival, and overall survival were similar between BCG studies (75-100%).

CONCLUSIONS

Carcinogen exposure that led to ESRD, BKV, HPV, immunosuppressive agents, and the immunosuppressed state likely contribute to the increased risk of bladder cancer after renal transplantation. Non-muscle invasive disease should be treated with transurethral resection. BCG can be safely used in transplant recipients and likely improves the disease course. Muscle-invasive disease should be treated with radical cystectomy, with special consideration to the dissection and urinary diversion choice. Chemotherapy and immune checkpoint inhibitors can be safely used in regionally advanced bladder cancer with potential benefit. mTOR inhibitors may reduce the risk of developing bladder cancer, and immunosuppression medications should be reduced if malignancy develops.

Management of de-novo urothelial carcinoma in transplanted patients

PURPOSE OF REVIEW

The aim of this article is to review incidence, risk factors, and optimal management of de-novo urothelial carcinoma in transplant recipients.

RECENT FINDINGS

There is a two to three-fold increased risk for de-novo malignant tumors after solid-organ transplantation, but there is currently no consensus regarding optimal management of de-novo urothelial carcinoma in transplanted patients. Known risk factors include polyomavirus BK, aristolochic acid, and smoking. Data suggest a higher rate of high-grade tumors, as well as predominantly higher stage at primary diagnosis, for both NMIBC and muscle-invasive bladder cancer (MIBC). Treatment for NMIBC includes TURB, mitomycin, and Bacille de Calmette-Guérin instillation with special concern to the immunosuppressive regime. Treatment of MIBC or advanced urothelial carcinoma includes radical cystectomy with chemotherapy if the patient is eligible. A screening should be performed in all transplant recipients, to allow early diagnosis.

SUMMARY

De-novo urothelial carcinoma in transplant recipients is more frequent than in the general population and these tumors were more likely to be high-grade tumors and diagnosed at an advanced stage. There is very little information available on the optimal treatment for these patients. However, aggressive treatment and a strict management according the given recommendations are of the utmost importance.

Cancer Risks in Solid Organ Transplant Recipients: Results from a Comprehensive Analysis of 72 Cohort Studies

Understanding the cancer risks in different transplant recipients helps early detection, evaluation, and treatment of post-transplant malignancies. Therefore, we performed a meta-analysis to determine the cancer risks at multiple sites for solid organ transplant recipients and their associations with tumor mutation burden (TMB), which reflects the immunogenicity. A comprehensive search of PubMed, Web of Science, EMBASE, Medline, and Cochrane Library was conducted. Random effects models were used to calculate the standardized incidence ratios (SIRs) versus the general population and determine the risks of different cancers. Linear regression (LR) was used to analyze the association between the SIRs and TMBs. Finally, seventy-two articles met our criteria, involving 2,105,122 solid organ transplant recipients. Compared with the general population, solid organ transplant recipients displayed a 2.68-fold cancer risk (SIR 2.68; 2.48-2.89; P <.001), renal transplant recipients displayed a 2.56-fold cancer risk (SIR 2.56; 2.31-2.84; P <.001), liver transplant recipients displayed a 2.45-fold cancer risk (SIR 2.45; 2.22-2.70; P <.001), heart and/or lung transplant recipients displayed a 3.72-fold cancer risk (SIR 3.72; 3.04-4.54; P <.001). The correlation coefficients between SIRs and TMBs were 0.68, 0.64, 0.59, 0.79 in solid organ recipients, renal recipients, liver recipients, heart and/or lung recipients, respectively. In conclusion, our study demonstrated that solid organ transplant recipients displayed a higher risk of some site-specific cancers, providing individualized guidance for clinicians to early detect, evaluate, and treat cancer among solid organ transplantation recipients. In addition, the increased cancer risk of solid organ transplant recipients is associated with TMB, suggesting that iatrogenic immunosuppression may contribute to the increased cancer risk in transplant recipients. (PROSPERO ID CRD42020160409).

Treatment options and predictive factors for recurrence and cancer-specific mortality in bladder cancer after renal transplantation: A multi-institutional analysis

OBJECTIVES

Bladder cancer (BC) in the transplanted population can represent a challenge owing to the immunosuppressed state of patients and the higher rate of comorbidities. The objective was to analyze the treatment of BC after renal transplant (RT), focusing on the mode of presentation, diagnosis, treatment options and predictive factors for recurrence.

MATERIAL AND METHODS

We conducted an observational prospective study with a retrospective analysis of 88 patients with BC after RT at 10 European centers. Clinical and oncologic data were collected, and indications and results of adjuvant treatment reviewed. The Kaplan-Meier method and uni- and multivariate Cox regression analyses were performed.

RESULTS

A total of 10,000 RTs were performed. Diagnosis of BC occurred at a median of 73 months after RT. Median follow-up was 126 months. Seventy-one patients (81.6%) had non-muscle invasive bladder cancer, of whom 29 (40.8%) received adjuvant treatment; of these, six (20.6%) received bacillus Calmette-Guérin and 20 (68.9%) mitomycin C. At univariate analysis, patients who received bacillus Calmette-Guérin had a significantly lower recurrence rate (P=.043). At multivariate analysis, a switch from immunosuppression to mTOR inhibitors significantly reduced the risk of recurrence (HR 0.24, 95% CI: 0.053-0.997, P=.049) while presence of multiple tumors increased it (HR 6.31, 95% CI: 1.78-22.3, P=.004). Globally, 26 patients (29.88%) underwent cystectomy. No major complications were recorded. Overall mortality (OM) was 32.2% (28 patients); the cancer-specific mortality was 13.8%.

CONCLUSIONS

Adjuvant bacillus Calmette-Guérin significantly reduces the risk of recurrence, as does switch to mTOR inhibitors. Multiple tumors increase the risk.

Polyomavirus Replication and Smoking Are Independent Risk Factors for Bladder Cancer After Renal Transplantation

BACKGROUND

Solid organ transplant recipients are at increased risk for developing malignancies. Polyomaviruses (PV) have been historically associated with experimental tumor development and recently described in association with renourinary malignancies in transplant patients. The aim of this study was to investigate the relationship between PV replication and smoking, and the development of malignant neoplasms in kidney transplant recipients.

METHODS

A retrospective case-control study was conducted for PV replication in all kidney biopsies and urine cytologies performed between 1998 and 2014 from kidney transplant recipients at the University of Maryland Medical Center. Polyomavirus-positive patients (n = 943) were defined as having any of the following: a kidney biopsy with PV associated nephropathy, any urine cytology demonstrating "decoy" cells, and/or significant polyomavirus BK viremia. Polyomavirus-negative matched patients (n = 943) were defined as lacking any evidence of PV replication. The incidence of malignancy (excluding nonmelanoma skin tumors) was determined in these 1886 patients and correlated with demographic data and history of smoking.

RESULTS

There was a 7.9% incidence of malignant tumors after a mean posttransplant follow-up of 7.9 ± 5.4 years. Among all cancer subtypes, only bladder carcinoma was significantly associated with PV replication. By multivariate analysis, only PV replication and smoking independently increased the risk of bladder cancer, relative risk, 11.7 (P = 0.0013) and 5.6 (P = 0.0053), respectively.

CONCLUSIONS

The findings in the current study indicate that kidney transplant recipients with PV replication and smoking are at particular risk to develop bladder carcinomas and support the need for long-term cancer surveillance in these patients.

BK nephropathy in the native kidneys of patients with organ transplants: Clinical spectrum of BK infection

Nephropathy secondary to BK virus, a member of the Papoviridae family of viruses, has been recognized for some time as an important cause of allograft dysfunction in renal transplant recipients. In recent times, BK nephropathy (BKN) of the native kidneys has being increasingly recognized as a cause of chronic kidney disease in patients with solid organ transplants, bone marrow transplants and in patients with other clinical entities associated with immunosuppression. In such patients renal dysfunction is often attributed to other factors including nephrotoxicity of medications used to prevent rejection of the transplanted organs. Renal biopsy is required for the diagnosis of BKN. Quantitation of the BK viral load in blood and urine are surrogate diagnostic methods. The treatment of BKN is based on reduction of the immunosuppressive medications. Several compounds have shown antiviral activity, but have not consistently shown to have beneficial effects in BKN. In addition to BKN, BK viral infection can cause severe urinary bladder cystitis, ureteritis and urinary tract obstruction as well as manifestations in other organ systems including the central nervous system, the respiratory system, the gastrointestinal system and the hematopoietic system. BK viral infection has also been implicated in tumorigenesis. The spectrum of clinical manifestations from BK infection and infection from other members of the Papoviridae family is widening. Prevention and treatment of BK infection and infections from other Papovaviruses are subjects of intense research.