Renal Cell Carcinoma and Kidney Transplantation: A Narrative Review

Increased risk of genitourinary cancer in kidney transplant recipients: a large-scale national cohort study and its clinical implications

PURPOSE

To investigate the risk of genitourinary (GU) cancer in kidney transplant recipients (KTRs) compared to that in the general population, focusing on potential risk factors and clinical implications.

METHODS

Using a national cohort of approximately 360,000 individuals, including 31,542 KTRs, we conducted a retrospective analysis of the data from 2007 to 2018. Propensity score matching was used to compare KTRs with a healthy population, adjusting for age, sex, diabetes, hypertension, and hypercholesterolemia.

RESULTS

We identified a significantly increased risk of GU cancers, particularly bladder and kidney cancers, in KTRs. Multivariate analysis revealed a higher risk of GU cancer associated with kidney transplantation [hazard ratio (HR) 2.133, 95% confidence interval (CI) 1.641-2.772] and hypercholesterolemia (HR 1.725, 95% CI 1.227-2.425), with older age and male sex also being significant risk factors. Conversely, no significant increase in prostate cancer risk was observed in KTRs compared to the general population.

CONCLUSION

This national cohort-based study indicated an increased risk of GU cancer in KTRs, underscoring the need for targeted cancer surveillance and pre- and post-transplant counseling. These findings provide valuable insights for the development of cancer surveillance programs for KTRs and highlight the necessity for further research in this field.

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.

Approach to Late Noninfectious Post-Transplant Complications

The management of noninfectious complications in kidney transplant recipients includes a broad spectrum of conditions, including metabolic issues, cardiovascular diseases, and malignancies, each presenting unique challenges for nephrologists managing these patients. Unlike infectious complications, these noninfectious issues require nuanced, multidisciplinary approaches for prevention, diagnosis, and management, emphasizing the need for personalized care plans. Cardiovascular disease is particularly significant, standing as the primary cause of death post-transplantation, with recent data indicating an overtaking of cancer death rates over infections among kidney transplant recipients. The intricacies of managing these patients, influenced by the burden of kidney disease and immunosuppression, highlight the importance of a collaborative care model. Although nephrologists may not directly treat all these conditions, their understanding of the unique aspects of transplant recipients is crucial. They play a pivotal role in coordinating care with specialists such as cardiologists, endocrinologists, hematologists, and oncologists, ensuring comprehensive management that addresses these specific post-transplant complications. This review discusses the epidemiology, underlying mechanisms, clinical manifestations, and management strategies of various noninfectious complications post-kidney transplant, with a focus on cardiovascular, metabolic, oncologic, and hematologic complications.

Clinical characteristics of renal cell carcinoma in the transplanted kidney in renal transplant recipients: a systematic scoping review

Background

Renal transplant recipients confront a substantially elevated susceptibility to renal cell carcinoma (RCC), particularly in their native kidneys as opposed to allografts.

Methods

In this systematic scoping review, exhaustive searches were conducted of the MEDLINE and EMBASE databases. Information was gathered on clinical manifestations, donor demographics, diagnostic intervals, tumor dimensions, histopathological characteristics, and therapeutic outcomes associated with RCC arising in allograft kidneys.

Results

The searches yielded a corpus of 42 case reports and 11 retrospective cohorts, encompassing a cohort of 274 patients. The majority of cases (75.4%) were clinically latent, discerned primarily through imaging modalities. Symptomatic presentations encompassed manifestations such as hematuria, elevated serum creatinine levels, abdominal discomfort, and graft-related pain. The mean temporal interval between renal transplantation and RCC diagnosis was calculated at 11.6 years, albeit displaying considerable variance. Notably, papillary and clear cell RCC emerged as the prevailing histopathological subtypes. However, the paucity of longitudinal follow-up data represents a notable caveat.

Conclusion

This investigation underscores the imperative of rigorous posttransplant surveillance regimes owing to the substantial prevalence of asymptomatic RCC instances. Future research should focus on clinical outcomes and cost-effectiveness of screening practices to develop preventive strategies.

A Rare Case of Donor-Derived Renal Cell Carcinoma in a Kidney Transplant Recipient

BACKGROUND The incidence of renal cell carcinoma (RCC) in transplanted kidneys is reported to be about 0.2%, which makes this case exceedingly rare. Risk factors include older age of the donors, smoking, obesity, and hypertension. Higher incidences of allograft RCC have been seen in patients who received a kidney from a deceased donor rather than from a living donor. CASE REPORT A 71-year-old woman with end-stage renal disease underwent deceased donor kidney transplantation (DDKT) 1 year before presentation. The immune-suppressive regimen was Envarsus, Myfortic, and prednisone. Allograft functioned with a baseline creatinine of 1.4-1.5 mg/dL. The patient presented due to recurring UTIs, which prompted the ultrasound that showed a mass on the allograft. Abdominal MRI demonstrated a 3.5-cm mass in the upper pole. Biopsy showed clear-cell RCC, Fuhrman nuclear grade 3. The patient underwent a partial nephrectomy. Following the nephrectomy, baseline serum creatinine was 1.7-2 mg/dL. The patient was discharged with immunosuppressive therapy consisting of Myfortic, prednisone, and Rapamune after diagnosis. CONCLUSIONS There are no standard treatment guidelines or optimal immune therapy for the management of allograft RCC in renal transplant recipients. Options include radical nephrectomy, nephron-sparing surgery (NSS), radiofrequency ablation (RFA), and active surveillance. According to a systematic review, the recurrence of cancer after partial nephrectomy was 3.6% after 3.1 years, which was similar to non-transplanted kidneys. There is not enough evidence to support screening for RCC in patients with transplanted kidneys, but constitutional symptoms like recurrent UTIs should prompt further investigation for potential malignancies in these patients.

Papillary Renal Cell Carcinoma in Transplanted Kidney and Xp11.2 Translocation/Transcription Factor E3-Rearranged Renal Cell Carcinoma in the Native Kidney: A Case Report

Concomitant renal cell carcinomas (RCC) of both native and allograft kidneys are extremely rare, and only a few cases have been reported in the available English literature. A particularly rare variant within the adult population is the Xp11.2 translocation/transcription factor E3 (TFE3)-rearranged RCC. Although few case reports of TFE3-rearranged RCC have been reported in children who underwent kidney transplantation (KT), no case of adults with TFE3-rearranged RCC following KT has been reported. Herein, we presented the radiological and pathological findings of a rare metachronous papillary RCC in the allograft kidney and TFE3-rearranged RCC in the native kidney. The TFE3-rearranged RCC in the native kidney exhibited slow expansion in size over five years. Radiologically, it appeared as a slightly enhanced, lobulated mass on contrast-enhanced CT. MRI revealed high signal intensity on T1-weighted images and low signal intensity on T2-weighted images.

Thermoablative Treatment of De Novo Tumor in Kidney Allograft

BACKGROUND

The overall cancer risk increases in transplant patients, including in kidney allografts. This study aimed to analyze the outcome of patients with kidney allograft malignant tumors who underwent percutaneous thermal ablation.

METHODS

We included 26 renal allograft tumors, including 7 clear-cell renal cell carcinoma (RCCs), 16 papillary RCCs, 1 clear-cell papillary RCC, and 2 tubulocystic RCCs, treated in 19 ablation sessions. Outcomes of thermal ablation therapy were assessed, including technical success, adverse events, local tumor progression, development of metastases, survival after thermal ablation, and changes in renal function.

RESULTS

Success rate was achieved in all ablation sessions (primary success rate: 96%; secondary success rate: 100%). No adverse events were observed in grades 3, 4, or 5. The median follow-up period was of 34 mo (15-69 mo). Two patients died during follow-up from a cause independent of renal cancer. The median decrease in estimated glomerular filtration rate 1 y after procedure was -4 (interquartile range, -7 to 0) mL/min/1.73 m 2 . One patient returned to dialysis within the year of the procedure.

CONCLUSIONS

Percutaneous thermal ablation shows convincing results for treating malignant renal graft tumors and should be a useful treatment option. The shorter hospitalization time, the advantage of avoiding a potentially challenging dissection of the transplant, and the excellent preservation of allograft function appear encouraging to extend this indication.

Pediatric Kidney Transplantation: Cancer and Cancer Risk

Children with end-stage kidney disease (ESKD) face a lifetime of complex medical care, alternating between maintenance chronic dialysis and kidney transplantation. Kidney transplantation has emerged as the optimal treatment of ESKD for children and provides important quality of life and survival advantages. Although transplantation is the preferred therapy, lifetime exposure to immunosuppression among children with ESKD is associated with increased morbidity, including an increased risk of cancer. Following pediatric kidney transplantation, cancer events occurring during childhood or young adulthood can be divided into two broad categories: post-transplant lymphoproliferative disorders and non-lymphoproliferative solid tumors. This review provides an overview of cancer incidence, types, outcomes, and preventive strategies in this population.

Renal Cell Carcinoma in End-Stage Kidney Disease and the Role of Transplantation

Kidney transplant patients have a higher risk of renal cell carcinoma (RCC) compared to non-transplanted end-stage kidney disease (ESKD) patients. This increased risk has largely been associated with the use of immunosuppression; however, recent genetic research highlights the significance of tissue specificity in cancer driver genes. The implication of tissue specificity becomes more obscure when addressing transplant patients, as two distinct metabolic environments are present within one individual. The oncogenic potential of donor renal tissue is largely unknown but assumed to pose minimal risk to the kidney transplant recipient (KTR). Our review challenges this notion by examining how donor and recipient microenvironments impact a transplant recipient's associated risk of renal cell carcinoma. In doing so, we attempt to encapsulate how ESKD-RCC and KTR-RCC differ in their incidence, pathogenesis, outcome, and approach to management.

How to manage renal masses in kidney transplant recipients? A collaborative review by the EAU-YAU kidney transplantation and renal cancer working groups

INTRODUCTION

Kidney transplant (KT) recipients have a four-times higher risk of renal malignancies compared to general population. As these patients frequently harbor bilateral or multifocal tumors, the management of renal masses is still under debate.

OBJECTIVE

To explore the current management of the native kidney masses in KT patients.

ACQUISITION OF EVIDENCE

We performed a literature search on MEDLINE/PubMed database. A number of 34 studies were included in the present review.

SYNTHESIS OF EVIDENCE

In frail patients with renal masses below 3 cm, active surveillance is a feasible alternative. Nephron-sparing surgery is not justified for masses in the native kidney. Radical nephrectomy is the standard treatment for post-transplant renal tumors of the native kidneys in KT recipients, with laparoscopic techniques leading to significantly less perioperative complication rates as compared to the open approach. Concurrent bilateral native nephrectomy at the time of transplantation can be considered in patients with renal mass and polycystic kidney disease, especially if no residual urinary output is present. Patients with localized disease and successful radical nephrectomy do not require immunosuppression adjustment. In metastatic cases, mTOR agents can ensure efficient antitumoral response, while maintaining proper immunosuppression in order to protect the graft.

CONCLUSIONS

Post-transplant renal cancer of the native kidneys is a frequent occurrence. Radical nephrectomy is most frequently performed for localized renal masses. A standardized and widely-approved screening strategy for malignancies of native renal units is yet to be implemented.

Benefits of Routine Screening for Renal Cell Carcinoma of Native Kidney in Renal Transplant Recipients

BACKGROUND

Renal-cell carcinoma (RCC) is the most common solid organ cancer in kidney transplantation recipients (KTRs).

BACKGROUND

Analyze the incidence, prognosis, and evolution of primitive kidney RCC in KTRs at our institution.

MATERIAL AND METHODS

Observational descriptive retrospective study in which all KTRs from January 2000 to December 2022 were included. We performed an annual abdominal ultrasound in all KTRs. Demographic and clinical data were collected. The surgical approach, location, size, histologic type, and tumor grade were analyzed. We assessed the coexistence of risk factors. We reported the appearance of tumors in other locations, changes in immunosuppressants (IS) after the diagnosis, and survival and recurrence rates observed during follow-up.

RESULTS

Eighteen RCCs of native kidneys were diagnosed with an incidence in our population of 1.08%. The majority were men (77.8%), with a mean age of 59.9 years. The pathologic analysis revealed 11 clear cell carcinomas, 6 papillary carcinomas, and 1 chromophobe cell carcinoma. The median tumor size was 2.7 cm. TNM stage was T1aN0M0 in 15 cases. Laparoscopy was performed to remove the tumor in most cases. All our patients underwent changes in IS therapy, with conversion to mammalian target of rapamycin inhibitors when possible and reduction of IS in all of them. After a mean follow-up of 78.6 months, survival was 100% without tumor recurrence. Seven of the patients were diagnosed with a new tumor in another location.

CONCLUSION

In our experience, annual abdominal ultrasound in KTRs may be an option for the early detection of RCC in native kidneys.

Genomic Fabrics of the Excretory System's Functional Pathways Remodeled in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most frequent form of kidney cancer. Metastatic stages of ccRCC reduce the five-year survival rate to 15%. In this report, we analyze the ccRCC-induced remodeling of the five KEGG-constructed excretory functional pathways in a surgically removed right kidney and its metastasis in the chest wall from the perspective of the Genomic Fabric Paradigm (GFP). The GFP characterizes every single gene in each region by these independent variables: the average expression level (AVE), relative expression variability (REV), and expression correlation (COR) with each other gene. While the traditional approach is limited to only AVE analysis, the novel REV analysis identifies the genes whose correct expression level is critical for cell survival and proliferation. The COR analysis determines the real gene networks responsible for functional pathways. The analyses covered the pathways for aldosterone-regulated sodium reabsorption, collecting duct acid secretion, endocrine and other factor-regulated sodium reabsorption, proximal tubule bicarbonate reclamation, and vasopressin-regulated water reabsorption. The present study confirms the conclusion of our previously published articles on prostate and kidney cancers that even equally graded cancer nodules from the same tumor have different transcriptomic topologies. Therefore, the personalization of anti-cancer therapy should go beyond the individual, to his/her major cancer nodules.

Screening for renal cell carcinoma in renal transplant recipients: a single-centre retrospective study

OBJECTIVES

The primary objective of our study was to evaluate the effectiveness of renal cell carcinoma (RCC) screening in renal transplant (RT) recipients.

DESIGN

Single-centre retrospective study.

SETTING AND PARTICIPANTS

1998 RT recipients who underwent RT at Memorial Hermann Hospital (MHH) Texas Medical Center (TMC) between 1 January 1999 and 31 December 2019 were included and we identified 16 patients (0.8%) with RCC. An additional four patients with RCC who underwent RT elsewhere but received follow-up at MHH TMC were also included. Subject races included white (20%), black (50%), Hispanic (20%) and Asian (10%).

OUTCOME MEASURES

The RCC stage at diagnosis and outcomes were compared between patients who were screening versus those who were not.

RESULTS

We identified a total of 20 patients with post-RT RCC, 75% of whom were men. The median age at diagnosis was 56 years. RCC histologies included clear cell (75%), papillary (20%) and chromophobe (5%). Patients with post-RT RCC who had screening (n=12) underwent ultrasound or CT annually or every 2 years, whereas eight patients had no screening. All 12 patients who had screening had early-stage disease at diagnosis (stage I (n=11) or stage II (n=1)) and were cured by nephrectomy (n=10) or cryotherapy (n=2). In patients who had no screening, three (37.5%) had stage IV RCC at diagnosis and all of whom died of metastatic disease. There was a statistically significant difference in RCC-specific survival in patients who were screened (p=0.01) compared with those who were not screened.

CONCLUSION

All RT recipients who had RCC diagnosed based on screening had early-stage disease and there were no RCC-related deaths. Screening is an effective intervention in RT recipients to reduce RCC-related mortality.

The Long Scientific Journey of Sirolimus (Rapamycin): From the Soil of Easter Island (Rapa Nui) to Applied Research and Clinical Trials on β-Thalassemia and Other Hemoglobinopathies

In this review article, we present the fascinating story of rapamycin (sirolimus), a drug able to induce γ-globin gene expression and increased production of fetal hemoglobin (HbF) in erythroid cells, including primary erythroid precursor cells (ErPCs) isolated from β-thalassemia patients. For this reason, rapamycin is considered of great interest for the treatment of β-thalassemia. In fact, high levels of HbF are known to be highly beneficial for β-thalassemia patients. The story of rapamycin discovery began in 1964, with METEI, the Medical Expedition to Easter Island (Rapa Nui). During this expedition, samples of the soil from different parts of the island were collected and, from this material, an antibiotic-producing microorganism (Streptomyces hygroscopicus) was identified. Rapamycin was extracted from the mycelium with organic solvents, isolated, and demonstrated to be very active as an anti-bacterial and anti-fungal agent. Later, rapamycin was demonstrated to inhibit the in vitro cell growth of tumor cell lines. More importantly, rapamycin was found to be an immunosuppressive agent applicable to prevent kidney rejection after transplantation. More recently, rapamycin was found to be a potent inducer of HbF both in vitro using ErPCs isolated from β-thalassemia patients, in vivo using experimental mice, and in patients treated with this compound. These studies were the basis for proposing clinical trials on β-thalassemia patients.

Immunosuppressive Therapy in Solid Organ Transplantation: Primer for Radiologists and Potential Complications

The availability of effective immunosuppressive medication is primarily responsible for the dramatic improvement in long-term graft survival rates after solid organ transplantation. The commonly used drugs include monoclonal/polyclonal antibodies, corticosteroids, calcineurin inhibitors (cyclosporine and tacrolimus), antimetabolites, mammalian target of rapamycin, and many novel drugs. Prolonged immunosuppression is accompanied by several well-described potentially life-threatening complications. In addition to drug-related side effects, recipients of solid organs are unavoidably at a higher risk for infections and malignancies. Select infections and malignancies in solid organ transplant patients have distinctive imaging findings, and radiologists play a crucial role in the timely diagnosis and management of these conditions.

2.5D MFFAU-Net: a convolutional neural network for kidney segmentation

BACKGROUND

Kidney tumors have become increasingly prevalent among adults and are now considered one of the most common types of tumors. Accurate segmentation of kidney tumors can help physicians assess tumor complexity and aggressiveness before surgery. However, segmenting kidney tumors manually can be difficult because of their heterogeneity.

METHODS

This paper proposes a 2.5D MFFAU-Net (multi-level Feature Fusion Attention U-Net) to segment kidneys, tumors and cysts. First, we propose a 2.5D model for learning to combine and represent a given slice in 2D slices, thereby introducing 3D information to balance memory consumption and model complexity. Then, we propose a ResConv architecture in MFFAU-Net and use the high-level and low-level feature in the model. Finally, we use multi-level information to analyze the spatial features between slices to segment kidneys and tumors.

RESULTS

The 2.5D MFFAU-Net was evaluated on KiTS19 and KiTS21 kidney datasets and demonstrated an average dice score of 0.924 and 0.875, respectively, and an average Surface dice (SD) score of 0.794 in KiTS21.

CONCLUSION

The 2.5D MFFAU-Net model can effectively segment kidney tumors, and the results are comparable to those obtained with high-performance 3D CNN models, and have the potential to serve as a point of reference in clinical practice.

Variation in Post-Transplant Cancer Incidence among Italian Kidney Transplant Recipients over a 25-Year Period

This cohort study examined 25-year variations in cancer incidence among 11,418 Italian recipients of kidney transplantation (KT) from 17 Italian centers. Cancer incidence was examined over three periods (1997-2004; 2005-2012; and 2013-2021) by internal (Incidence rate ratio-IRR) and external (standardized incidence ratios-SIR) comparisons. Poisson regression was used to assess trends. Overall, 1646 post-transplant cancers were diagnosed, with incidence rates/1000 person-years ranging from 15.5 in 1997-2004 to 21.0 in 2013-2021. Adjusted IRRs showed a significant reduction in incidence rates across periods for all cancers combined after exclusion of nonmelanoma skin cancers (IRR = 0.90, 95% confidence interval-CI: 0.76-1.07 in 2005-2012; IRR = 0.72, 95% CI: 0.60-0.87 in 2013-2021 vs. 1997-2004; P_trend < 0.01). In site-specific analyses, however, significant changes in incidence rates were observed only for Kaposi's sarcoma (KS; IRR = 0.37, 95% CI: 0.24-0.57 in 2005-2012; IRR = 0.09, 95% CI: 0.04-0.18 in 2013-2021; P_trend < 0.01). As compared to the general population, the overall post-transplant cancer risk in KT recipients was elevated, with a decreasing magnitude over time (SIR = 2.54, 95% CI: 2.26-2.85 in 1997-2004; SIR = 1.99, 95% CI: 1.83-2.16 in 2013-2021; P_trend < 0.01). A decline in SIRs was observed specifically for non-Hodgkin lymphoma and KS, though only the KS trend retained statistical significance after adjustment. In conclusion, apart from KS, no changes in the incidence of other cancers over time were observed among Italian KT recipients.

Management of renal cell carcinoma in transplant kidney: a systematic review and meta-analysis

INTRODUCTION

After transplantation, approximately 10% of renal cell carcinomas are detected in graft kidneys. These tumors (gRCC) present surgeons with the difficulty of finding a treatment that guarantees both oncological clearance and maintenance of function. We conducted a systematic review and an individual patient data meta-analysis on the oncology, safety and functional outcomes of the available treatments for gRCC.

EVIDENCE ACQUISITION

A systematic search was performed across MEDLINE, EMBASE, and Web of Science including any study reporting perioperative, functional and survival outcomes for patients undergoing graft nephrectomy (GN), partial nephrectomy (PN) or thermal ablation (TA) for gRCC. Quade's ANCOVA, Spearman Rho and Pearson χ², Kaplan-Meier, Log-rank and Standard Cox regression and other tests were used to compare treatments. Studies' quality was evaluated using a modified version of Newcastle Ottawa Scale.

EVIDENCE SYNTHESIS

A number of 29 studies (357 patients) were included. No differences between TA and PN were found in terms of safety, functional and oncological outcomes for T1a gRCCs. When applied to pT1b gRCC, PN showed no difference in complications, progression or cancer-specific deaths compared to smaller lesions; PN validity for pT2 gRCCs should be considered unverified due to lack of sufficient evidence. The efficacy and safety of PN or TA for multiple gRCC remain controversial. In case of non-functioning, large (T≥2), complicated or metastatic gRCCs, GN appears to be the most reasonable choice. Quality of evidence ranged from very low to moderate. Studies with large cohorts and longer follow-up are still needed to clarify oncological and functional differences.

CONCLUSIONS

PN and TA might be offered as a nephron-sparing treatment in patients with T1a gRCC. There is no significant difference between these options and GN in terms of oncological outcomes and complications. PN and TA offer similar functional outcomes and graft preservation. PN for T1b gRCC seems feasible and safe, but its validity should be considered unverified.

Renal cell carcinoma of different pathological types in bilateral native kidneys of a kidney transplant recipient: A case report and literature review

Patients after kidney transplantation have a much higher risk of developing malignant tumors than the general population. And the native kidney is an organ relatively susceptible to malignant tumors after renal transplantation. However, the simultaneous development of bilateral renal tumors is very rare; especially the bilateral native kidneys harbor different pathological types of renal cell carcinoma (RCC). We report a case of a patient who developed malignant tumors in both native kidneys nearly 19 years after renal transplantation. This patient underwent bilateral laparoscopic radical nephrectomy, and postoperative pathological examination showed clear cell RCC on the left native kidney and papillary RCC on the right one. And the early detection and surgical treatment resulted in a good prognosis. The literature related to the diagnosis and treatment of bilateral RCC after renal transplantation is also reviewed.

Bilateral Native Kidney Papillary Renal Cell Carcinomas in a 11-Year-Old Renal Transplant Patient

Renal cell carcinomas (RCCs) are the most common renal tumors in adults and are usually sporadic and unilateral. Renal transplant recipients have an increased risk of developing RCC. RCC development after kidney transplantation is very rarely reported in children. We present a 11-year-old boy who had cadaveric kidney transplantation for kidney failure 2 years ago. He was under immunosuppressive therapy and presented with microscopic hematuria. An ultrasound (US) revealed bilateral solid renal masses. Further cross-sectional imaging showed a 60 × 70 × 60-mm right renal mass with claw sign and a 5 × 6 × 6-mm mass in the left renal lower pole. A bilateral radical nephroureterectomy of native kidneys was performed. The pathology revealed bilateral papillary RCC without TFE3 upregulation. The patient was kept on low-dose immunosuppressive therapy in the perioperative period. He received no chemotherapy but a close radiological surveillance was undertaken. He is tumor-free 2 years after the operation. RCC is a rare tumor for children and bilateralism is even rarer. The child had a history of chronic kidney disease, peritoneal dialysis, and immunosuppressive therapy. As there are no standardized protocols regarding imaging in transplanted kidneys routine surveillance, US follow-up should also focus on detecting malignancy.

Cryoablation for Renal Cell Carcinoma Prior to Liver Transplantation: A Case Report

Extrahepatic malignancies are a relatively rare incidental finding during liver transplant work-up that provides a significant barrier to continued transplant evaluation and requires treatment to limit the risk of recurrence. There have only been 11 previously reported cases of pre-liver transplant renal cell carcinoma (RCC), of which all underwent partial or radical nephrectomy. Percutaneous cryoablation therapy has been gaining acceptance as a curative treatment alternative for RCC and is a new therapeutic standard for patients who are poor candidates for surgical resection. Recent studies have demonstrated the safety and efficacy of cryoablation for RCC in native kidneys and in solid masses in kidney allografts, but there is no data on the efficacy or recurrence of RCC when cryoablation is used for the treatment of RCC in a native kidney prior to solid organ transplantation. The patient underwent percutaneous cryoablation therapy of a T1a RCC of the native kidney 10 months prior to orthotopic liver transplant (OLT) without subsequent partial or radical nephrectomy. At seven years post-ablation therapy, the patient has no evidence of tumor recurrence despite immunosuppressive therapy post-transplantation. Cryoablation is potentially a safe and highly effective means of treating RCC in patients who are not candidates for nephrectomy secondary to complications associated with end-stage liver disease. In our case, the patient was treated with cryoablation and received standard post-transplant immunosuppression without recurrence of RCC at seven years. More studies are needed to determine inclusion and exclusion criteria for cryoablation and to confirm long-term efficacy as well as a strategy for duration and frequency of surveillance in these patients.

The interplay between non-coding RNAs and Wnt/ß-catenin signaling pathway in urinary tract cancers: from tumorigenesis to metastasis

Non-coding RNAs (ncRNAs) are emerging as important regulators in various pathological conditions including tumorigenesis, metastasis, and drug resistance in human cancers. Oncogenic or tumor suppressor ncRNAs exert prominent effects on cell proliferation, migration and invasion in cancer cells through modulating various signaling pathways including Wnt/β-catenin. Upregulation of the oncogenic Wnt/β-catenin pathway was reported to be implicated in multiple human cancers including breast, liver, colorectal, and urothelial cancers. Therefore, identifying interactions between ncRNAs and canonical Wnt signaling components may represent novel therapeutic targets for better treatment and management of cancer. In this review, we summarized the recent findings about miRNA/lncRNA-dependent mechanisms that regulate Wnt/β-catenin signaling involved in tumorigenesis and metastasis of urinary tract cancers.

Malignancies in adult kidney transplant candidates and recipients: current status

Posttransplant malignancies, particularly recurrent and de novo, in solid organs including kidney transplant recipients (KTRs) are a significant complication associated with substantial mortality, largely attributed to long-term immunosuppression necessary to maintain allograft tolerance. Older age at transplantation and oncogenic virus infection along with pretransplant malignancies are among the main factors contributing to the risk of cancer in this population. As the mean age of transplant candidates rises, the rate of transplant recipients with pretransplant malignancies also increases. The eligibility criteria for transplantation in patients with prior cancer have recently changed. The overall risk of posttransplant malignancies is at least double after transplantation including KTRs relative to the general population, most pronounced for skin cancers associated with UV radiation and virally-mediated tumors. The risk of renal cell carcinoma is specifically increased in the kidney transplant population. The therapy of cancer in transplant patients is associated with risk of higher toxicity, and graft rejection and/or impairment, which poses a unique challenge in the management. Reduction of immunosuppression and the use of mTOR inhibitors are common after cancer diagnosis, although optimal immunosuppression for transplant recipients with cancer remains undefined. Suboptimal cancer treatment contributing to a worse prognosis has been reported for malignancies in this population. In this article, we focus on the prevalence and outcomes of posttransplant malignancies, cancer therapy including a short overview of immunotherapy, cancer screening and prevention strategies, and immunosuppression as a cancer risk factor. The 2020/2021 recommendations of the Kidney Diseases Improving Global Outcome (KDIGO) and American Society of Transplantation (AST) for transplant candidates with a history of cancer are presented.

Small renal masses in kidney transplantation: overview of clinical impact and management in donors and recipients

Kidney transplantation is the best replacement treatment for the end-stage renal disease. Currently, the imbalance between the number of patients on a transplant list and the number of organs available constitutes the crucial limitation of this approach. To expand the pool of organs amenable for transplantation, kidneys coming from older patients have been employed; however, the combination of these organs in conjunction with the chronic use of immunosuppressive therapy increases the risk of incidence of graft small renal tumors. This narrative review aims to provide the state of the art on the clinical impact and management of incidentally diagnosed small renal tumors in either donors or recipients. According to the most updated evidence, the use of grafts with a small renal mass, after bench table tumor excision, may be considered a safe option for high-risk patients in hemodialysis. On the other hand, an early small renal mass finding on periodic ultrasound-evaluation in the graft should allow to perform a conservative treatment in order to preserve renal function. Finally, in case of a renal tumor in native kidney, a radical nephrectomy is usually recommended.

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.