Incidence and Mortality of Renal Cell Carcinoma after Kidney Transplantation: A Meta-Analysis. J Clin Med. 2019;8:530. [PMID: 30999706 PMCID: PMC6517974 DOI: 10.3390/jcm8040530]

Predicting kidney allograft survival with explainable machine learning

INTRODUCTION

Despite significant progress over the last decades in the survival of kidney allografts, several risk factors remain contributing to worsening kidney function or even loss of transplants. We aimed to evaluate a new machine learning method to identify these variables which may predict the early graft loss in kidney transplant patients and to assess their usefulness for improving clinical decisions.

MATERIAL AND METHODS

A retrospective cohort study was carried out with 627 kidney transplant patients followed at least three months. All these data were pre-processed, and their selected features were used to develop an automatically working a machine learning algorithm; this algorithm was then applied for training and parameterization of the model; and finally, the tested model was then used for the analysis of patients' features that were the most impactful for the prediction of clinical outcomes. Our models were evaluated using the Area Under the Curve (AUC), and the SHapley Additive exPlanations (SHAP) algorithm was used to interpret its predictions.

RESULTS

The final selected model achieved a precision of 0.81, a sensitivity of 0.61, a specificity of 0.89, and an AUC value of 0.84. In our model, serum creatinine levels of kidney transplant patients, evaluated at the hospital discharge, proved to be the most important factor in the decision-making for the allograft loss. Patients with a weight equivalent to a BMI closer to the normal range prior to a kidney transplant are less likely to experience graft loss compared to patients with a BMI below the normal range. The age of patients at transplantation and Polyomavirus (BKPyV) infection had significant impact on clinical outcomes in our model.

CONCLUSIONS

Our algorithm suggests that the main characteristics that impacted early allograft loss were serum creatinine levels at the hospital discharge, as well as the pre-transplant values such as body weight, age of patients, and their BKPyV infection. We propose that machine learning tools can be developed to effectively assist medical decision-making in kidney transplantation.

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.

Incidence of renal cell carcinoma after solid organ transplantation: a systematic review and meta-analysis

BACKGROUND

The incidence rate of malignant tumors after solid organ transplantation is higher than the normal population. The aim of our study is to identify the risk of renal cell carcinoma (RCC) after liver, kidney, heart and lung transplantation, respectively, and suggest that transplant patients can be screened early for tumors to avoid risk.

METHODS

PubMed, Embase and the Cochrane Library from their inception until August 16,2023. Retrospective and cohort studies which focus on the statistical data of standardized incidence ratios (SIRs) of RCC after solid organ transplantation (SOT) more than one year have been included and extracted. The study was registered with PROSPERO, CRD4202022343633.

RESULTS

Sixteen original studies have been included for meta-analysis. Liver transplantation could increase the risk of RCC (SIR = 0.73, 95%CI: 0.53 to 0.93) with no heterogeneity(P = 0.594, I2 = 0.0%). And kidney transplantation could increase the risk of RCC(8.54, 6.68 to 10.40; 0.000,90.0%). Besides, heart and lung transplantation also could increase the risk of RCC(SIR = 0.73, 95%CI: 0.53 to 0.93; SIR = 1.61, 95%CI:0.50 to 2.71). Moreover, significance could also be found in most subgroups, especially the European group and retrospective study group. What's more, after removing studies which have a greater impact on the overall outcome in RCC rate after kidney transplantation, heterogeneity did not solve and significant different was also observed in the European group (7.15, 5.49 to 8.81; 0.000, 78.6%).

CONCLUSION

Liver, kidney, heart and lung transplantation patients have an increased risk of processing RCC compared to the general population and most subgroups, especially in geographic location of European subgroup, which suggested that patients should be screened frequently after transplantation.

Investigation of Underlying Biological Association and Targets between Rejection of Renal Transplant and Renal Cancer

Background

Post-renal transplant patients have a high likelihood of developing renal cancer. However, the underlying biological mechanisms behind the development of renal cancer in post-kidney transplant patients remain to be elucidated. Therefore, this study aimed to investigate the underlying biological mechanism behind the development of renal cell carcinoma in post-renal transplant patients.

Methods

Next-generation sequencing data and corresponding clinical information of patients with clear cell renal cell carcinoma (ccRCC) were obtained from The Cancer Genome Atlas Program (TCGA) database. The microarray data of kidney transplant patients with or without rejection response was obtained from the Gene Expression Omnibus (GEO) database. In addition, statistical analysis was conducted in R software.

Results

We identified 55 upregulated genes in the transplant patients with rejection from the GEO datasets (GSE48581, GSE36059, and GSE98320). Furthermore, we conducted bioinformatics analyses, which showed that all of these genes were upregulated in ccRCC tissue. Moreover, a prognosis model was constructed based on four rejection-related genes, including PLAC8, CSTA, AIM2, and LYZ. The prognosis model showed excellent performance in prognosis prediction in a ccRCC cohort. In addition, the machine learning algorithms identified 19 rejection-related genes, including PLAC8, involved in ccRCC occurrence. Finally, the PLAC8 was selected for further research, including its clinical and biological role.

Conclusion

In all, our study provides novel insight into the transition from the rejection of renal transplant to renal cancer. Meanwhile, PLAC8 could be a potential biomarker for ccRCC diagnosis and prognosis in post-kidney transplant patients.

To screen or not to screen renal cell cancer in a kidney transplant patient

Background

The prevalence of malignancies is higher among kidney transplant recipients (KTR) than general population. Although the incidence of renal cell cancer (RCC) after KTR was reported as 0.6 % with a high mortality rate of 13.9 %, none of the guidelines except the European Best Practice Guideline (EBPG) recommends RCC screening based on cost-effectiveness and lack of solid evidence. The EBPG recommends RCC screening in native kidneys (not the allograft) by ultrasonography (USG) every 1-3 years.

Case description

A 55-year-old male patient who had a kidney transplant from a living donor 14 years before, presented with sudden onset uncontrolled hypertension (180/110 mmHg) and rapid deterioration in graft functions (increase in serum creatinine to two-times baseline). Evaluations revealed RCC in the allograft. Abdominal pain, hematuria, fever, weight loss, flu-like syndrome, recurrent urinary tract infections, weakness, hypertension, and allograft dysfunction are reported as the main complaints and signs of RCC in KTR patients. Our patient's findings were hypertension and allograft dysfunction.

Conclusion

It is essential to follow EBPG for KTR and not to forget the annual USG for screening of RCC both in native kidneys and allograft. HIPPOKRATIA 2023, 27 (2):69-71.

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.

Circular RNA-regulated autophagy is involved in cancer progression

Circular RNAs (circRNAs) are a sort of long, non-coding RNA molecules with a covalently closed continuous ring structure without 5'-3' polarity and poly-A tail. The modulative role of circRNAs in malignant diseases has been elucidated by many studies in recent years via bioinformatics and high-throughput sequencing technologies. Generally, circRNA affects the proliferative, invasive, and migrative capacity of malignant cells via various mechanisms, exhibiting great potential as novel biomarkers in the diagnoses or treatments of malignancies. Meanwhile, autophagy preserves cellular homeostasis, serving as a vital molecular process in tumor progression. Mounting studies have demonstrated that autophagy can not only contribute to cancer cell survival but can also induce autophagic cell death in specific conditions. A growing number of research studies have indicated that there existed abundant associations between circRNAs and autophagy. Herein, we systemically reviewed and discussed recent studies on this topic in different malignancies and concluded that the circRNA–autophagy axis played crucial roles in the proliferation, metastasis, invasion, and drug or radiation resistance of different tumor cells.

Malignancy Diseases in Kidney Transplantation, Clinical Outcomes, Patient, and Allograft Survival: A Case-Control Study

BACKGROUND

Malignancy is a well-known complication in patients after kidney transplantation (KT), but its effect on posttransplant outcomes, allograft, and patient survival remains unexplored. The aim of this study is to report the impact of the comorbidity on clinical outcome, function, and failure of an allograft kidney.

METHODS

This case-control study included 101 KT patients. Twenty-six patients who developed cancer (CA) were assigned to the case group and 75 to the control group. Statistical analysis was performed using logistic regression models, and graft survival was analyzed using the Kaplan-Meier curve.

RESULTS

Non-melanoma skin CA was the most common malignancy, accounting for almost 60% of cases, followed by stomach CA, prostate CA, and lymphoproliferative diseases (7.70% each). Difference in graft and patient survival was not significant between the two groups (P > .05). A tumor in nonfunctioning in the first nonfunctioning KT was identified in 1 KT patient with a second allograft and by anatomopathological was detect Fuhrman grade II renal cell carcinoma. This KT patient was in good clinical condition with serum creatinine level of 1.5 mg/dL.

CONCLUSIONS

No association was observed between CA development and risk factors, including family history and smoking habit, and no differences in allograft and patient survival were found. Nevertheless, in our data, CA in KT patients occurred early after transplantation. Renal cell carcinoma in allograft failure was identified in a patient; that suggested that nephrectomy of kidney failure must be performed to avoid patient allosensitization and neoplasia. Thus, we suggest continuous screening of malignancy diseases for KT patients.

Sunitinib-related high-grade proteinuria and allograft dysfunction in a kidney recipient: a rare case report

Background

Sunitinib-induced high-grade proteinuria and irreversible renal allograft dysfunction are rare conditions. Here, we present a patient who had received renal allograft and later developed metastatic clear cell renal cell carcinoma(cc-mRCC), for which he was prescribed sunitinib. High-grade proteinuria, hypoalbuminemia, peripheral edema and renal allograft dysfunction (manifesting as an increase in the serum creatinine concentration) occurred 5 months after sunitinib prescription.

Case presentation

The patient was a 58-year-old male who had end-stage renal disease with regular hemodialysis through arteriovenous fistula for 17 years since 1998 and received a renal allograft from a deceased kidney donor in 2015. Unfortunately, in 2019, the patient developed cc-mRCC originating from the left native kidney. We suggested a needle biopsy on left native kidney or radical left nephrectomy, but the patient refused. Sunitinib was prescribed. Follow-up urine analysis showed proteinuria (500 mg/dL) 2 weeks after sunitinib prescription. He was hospitalized 5 months later because of body weight gain, decreased urine output, pitting edema of both lower extremities, and shortness of breath. The image studies showed progression in his cc-mRCC. His serum creatinine level and spot urine protein at admission increased to 4.26 mg/dL and 300 mg/dL, respectively. He agreed on a biopsy for the renal allograft and the pathology studies showed focal segmental glomerulosclerosis, acute interstitial nephritis, and acute tubular injury. Based on the time sequence of clinical presentations with the laboratory and pathological findings, sunitinib-induced renal allograft dysfunction secondary to high-grade proteinuria was most likely. Despite of discontinuation of sunitinib and increased dose of everolimus, renal impairment progressed. Thus, he had to receive hemodialysis starting 2 week after hospitalization. Unfortunately, the patient died of advanced metastasis despite of aggressive medical treatments 3 weeks after admission.

Conclusion

This case report is a reminder that renal allograft dysfunction can happen secondary to proteinuria after taking sunitinib. Hence, clinicians must regularly check renal function and urine protein for renal allograft recipients. Monitoring and modifying drug prescription, especially sunitinib, is necessary if persistent proteinuria accompanied by deteriorating serum creatinine level occurs. Renal biopsy may be considered if more evidence is required to make a differential diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02789-5.

Incidence, management and treatment outcomes of renal malignancy in a post-transplant recipient at a tertiary care centre: A 16-year experience

Introduction and Objective:

Although the incidence of malignancy in renal transplant recipients is on the rise owing to boom in the post-transplant immunosuppressive therapy, there is paucity of literature regarding their reporting and management. In this study, we report the incidence of de novo renal malignancies, post-renal transplantation at our centre over a 16-year period and discuss their management.

Methods:

All patients who underwent renal transplantation at our department between March 2004 and February 2020 were included and retrospectively reviewed. We analysed the incidence of renal malignancy both in the native kidney and the graft, histological subtype, time to and type of treatment.

Results:

A total of 376 patients underwent renal transplantation. Mean age of recipients was 48.2 and 52.15 years among those who developed cancer. 13 (2.93%) of 376 recipients developed urogenital malignancy, of whom 8 had renal cell carcinoma (RCC) in their native kidneys and 1 in the allograft. Transitional cell carcinoma (TCC) of renal pelvis was noted in three patients with one concomitant TCC of bladder. No treatment-related graft losses occurred in the native kidney malignancy. Patients with RCC underwent nephrectomy while TCC of renal pelvis underwent nephroureterectomy with bladder cuff excision. Transurethral resection was done for bladder tumour. All patients were followed up as per standard protocol.

Conclusion:

A rise in urological post-transplant malignancies mandates regular surveillance after renal transplantation to ensure early detection of de novo malignancies and early initiation of treatment. Goal should be to minimise adverse graft outcomes with no compromise on oncological outcomes.

Level of evidence:

Not applicable

Cancer Screening in Solid Organ Transplant Recipients: A Focus on Screening Liver, Lung, and Kidney Recipients for Cancers Related to the Transplanted Organ

Over the last few decades, the life expectancy of solid organ transplant recipients (SOTRs) has improved significantly. With SOTRs living longer, more recipients are dying from cancer. There is a reported 2- to 3-fold increased risk of cancer-specific mortality in SOTRs compared with the general population. Cancer in an SOTR can be de novo, recurrent, or donor-derived. Cancer screening in this population is crucial, as early detection and treatment may improve outcomes. In the absence of randomized controlled trials dedicated to SOTRs, clinicians rely on clinical practice guidelines from regional and national transplant societies; however, these may vary considerably across jurisdictions and transplanted organ. At present, no widely accepted consensus exists for cancer screening protocols in SOTRs, particularly with regard to screening for malignancy related to transplanted organ. Some SOTRs may be at higher risk of malignancies within the allograft. This is particularly the case in lung and liver recipients, though less common in kidney recipients who are at increased risk of developing renal cell cancer in their native kidneys. This increased risk has not been uniformly incorporated into screening recommendations for SOTRs. In this review, we summarize the cancer screening recommendations for SOTRs from various transplant organizations based on transplanted organ. This review also discusses the complexity and controversies surrounding screening of cancer in the allograft and future avenues to improve cancer detection in this context. More studies specific to SOTRs are required to form generalizable and evidence-based cancer screening guidelines, particularly with respect to cancer screening in the allograft.

Ampelopsin Inhibits Cell Viability and Metastasis in Renal Cell Carcinoma by Negatively Regulating the PI3K/AKT Signaling Pathway

Background

Previous studies have shown that Ampelopsin has an inhibitory effect on human tumors. However, the effect of Ampelopsin on renal cell carcinoma (RCC) is rarely reported. Therefore, this study aims to explain the role of Ampelopsin in RCC.

Methods

Different concentrations of Ampelopsin (0, 10, 25, 50, and 100 μM) were used to treat 786-O cells. Cell viability was detected by MTT assay, colony formation assay, and flow cytometry assay. Transwell assay and Wound healing assay were used to detect cell migration and invasion. Western blot analysis was applied to detect protein expression.

Results

Ampelopsin inhibited cell proliferation and induced apoptosis in RCC. And Ampelopsin can inhibit cell migration and invasion in RCC. All these results changed in a dose-dependent manner. Ampelopsin (100 uM) had the strongest inhibitory effect on cell viability and metastasis. In addition, Ampelopsin negatively regulated the PI3K/AKT signaling pathway in RCC cells. Moreover, Ampelopsin was only cytotoxic to RCC cells.

Conclusion

Ampelopsin inhibits cell viability and metastasis in RCC by negatively regulating the PI3K/AKT signaling pathway.

Renal toxicity of targeted therapies for renal cell carcinoma in patients with normal and impaired kidney function

The introduction of novel targeted therapies during the last 2 decades has led to a significant improvement in patients' clinical outcomes with renal cell carcinoma. However, this improvement came at the price of a whole new spectrum of adverse events, including renal toxicity. Systemic treatment of patients with kidney neoplasms who often present with impairment of kidney function, even prior to treatment, poses an increasing diagnostic and therapeutic challenge for clinicians. Common lifestyle-related comorbidities, i.e., hypertension and diabetes, may contribute to further impairment of kidney function. The lack of official guidelines and the exclusion of patients with reduced kidney function from the clinical trials of recently approved drugs complicate the issue even further. Early detection and correct management of renal toxic effects are crucial to preserve kidney function and ensure the optimal administration of life-prolonging therapies. This review presents detailed information on the renal toxicities of three groups of drugs commonly used in renal cell carcinoma treatment: tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and immune checkpoint inhibitors. We outline the incidence and underlying mechanisms of renal adverse effects with a focus on patients on renal replacement therapy, as well as present suggestions for their management.

Use of dual-energy CT for renal mass assessment

Although dual-energy CT (DECT) may prove useful in a variety of abdominal imaging tasks, renal mass evaluation represents the area where this technology can be most impactful in abdominal imaging compared to routinely performed contrast-enhanced-only single-energy CT exams. DECT post-processing techniques, such as creation of virtual unenhanced and iodine density images, can help in the characterization of incidentally discovered renal masses that would otherwise remain indeterminate based on post-contrast imaging only. The purpose of this article is to review the use of DECT for renal mass assessment, including its benefits and existing limitations. KEY POINTS: • If DECT is selected as the scanning mode for most common abdominal protocols, many incidentally found renal masses can be fully triaged within the same exam. • Virtual unenhanced and iodine density DECT images can provide additional information when renal masses are discovered in the post-contrast-only setting. • For renal mass evaluation, virtual unenhanced and iodine density DECT images should be interpreted side-by-side to troubleshoot pitfalls that can potentially lead to erroneous interpretation.

Tubulocystic Renal Cell Carcinoma of the Native Kidney in a Renal Transplant Recipient: A Rare Case Report

Tubulocystic renal cell carcinoma (TCC) is a rare and newly recognized variant of renal cell carcinoma, which may mimic benign cystic disease of the kidney. To our knowledge, we present the first reported case of a patient who, despite standard preoperative workup, developed TCC of his native kidney soon after receiving kidney transplantation. He was appropriately treated with native nephrectomy and has had no signs of reoccurrence 7 years postoperatively. Given the significant risk of malignancy in renal transplant patients, this case emphasizes the need for close monitoring of native cystic disease before and after transplantation, with low threshold to proceed with surgical intervention.

Characteristics and Graft Survival of Kidney Transplant Recipients with Renal Cell Carcinoma

BACKGROUND

The incidence of renal cell carcinoma (RCC) is higher in kidney transplant recipients (KTRs) compared to the general population. However, the risk factors and outcomes based on the diagnosis of RCC after kidney transplantation are limited.

METHODS

We analyzed risk factors for the development of RCC in KTRs transplanted at our institution between 1994 and 2016. We compared the incidence of graft failure and mortality in KTRs with RCC to matched controls using 5:1 event density sampling. Identifying the risk factors of RCC and patient and graft survival were outcomes of interest.

RESULTS

There were 4,178 KTRs performed at our institution during the study period, and 51 patients were diagnosed with RCC. Recipients were followed until graft failure or death. We did not identify commonly looked at baseline characteristics associated with the risk of RCC. Comparing KTRs with RCC to matched controls, RCC patients were younger (47.5 vs. 49.6 years, p < 0.01), received basiliximab induction more commonly (p = 0.01), had hypertension and glomerulonephritis as causes of end-stage renal disease (p = 0.01), and were more likely to be smokers (p < 0.01). RCC was significantly associated with death-censored graft failure (adjusted hazard ratio [HR]: 1.76; 95% CI: 1.02-3.03; p = 0.04) but not patient death (adjusted HR: 0.95; 95% CI: 0.50-1.83; p = 0.89).

CONCLUSION

In our experience, RCC had a detrimental impact on graft survival among KTRs, highlighting the potential benefit of early diagnosis and optimal immunosuppression management in optimizing graft survival.

Role for contrast-enhanced ultrasound in assessing complications after kidney transplant

Kidney transplantation (KT) is an effective treatment for end-stage renal disease. Despite their rate has reduced over time, post-transplant complications still represent a major clinical problem because of the associated risk of graft failure and loss. Thus, post-KT complications should be diagnosed and treated promptly. Imaging plays a pivotal role in this setting. Grayscale ultrasound (US) with color Doppler analysis is the first-line imaging modality for assessing complications, although many findings lack specificity. When performed by experienced operators, contrast-enhanced US (CEUS) has been advocated as a safe and fast tool to improve the accuracy of US. Also, when performing CEUS there is potentially no need for further imaging, such as contrast-enhanced computed tomography or magnetic resonance imaging, which are often contraindicated in recipients with impaired renal function. This technique is also portable to patients' bedside, thus having the potential of maximizing the cost-effectiveness of the whole diagnostic process. Finally, the use of blood-pool contrast agents allows translating information on graft microvasculature into time-intensity curves, and in turn quantitative perfusion indexes. Quantitative analysis is under evaluation as a tool to diagnose rejection or other causes of graft dysfunction. In this paper, we review and illustrate the indications to CEUS in the post-KT setting, as well as the main CEUS findings that can help establishing the diagnosis and planning the most adequate treatment.

Recent Advances and Clinical Outcomes of Kidney Transplantation

Recent advances in surgical, immunosuppressive and monitoring protocols have led to the significant improvement of overall one-year kidney allograft outcomes. Nonetheless, there has not been a significant change in long-term kidney allograft outcomes. In fact, chronic and acute antibody-mediated rejection (ABMR) and non-immunological complications following kidney transplantation, including multiple incidences of primary kidney disease, as well as complications such as cardiovascular diseases, infections, and malignancy are the major factors that have contributed to the failure of kidney allografts. The use of molecular techniques to enhance histological diagnostics and noninvasive surveillance are what the latest studies in the field of clinical kidney transplant seem to mainly focus upon. Increasingly innovative approaches are being used to discover immunosuppressive methods to overcome critical sensitization, prevent the development of anti-human leukocyte antigen (HLA) antibodies, treat chronic active ABMR, and reduce non-immunological complications following kidney transplantation, such as the recurrence of primary kidney disease and other complications, such as cardiovascular diseases, infections, and malignancy. In the present era of utilizing electronic health records (EHRs), it is strongly believed that big data and artificial intelligence will reshape the research done on kidney transplantation in the near future. In addition, the utilization of telemedicine is increasing, providing benefits such as reaching out to kidney transplant patients in remote areas and helping to make scarce healthcare resources more accessible for kidney transplantation. In this article, we discuss the recent research developments in kidney transplants that may affect long-term allografts, as well as the survival of the patient. The latest developments in living kidney donation are also explored.

Promises of Big Data and Artificial Intelligence in Nephrology and Transplantation

Kidney diseases form part of the major health burdens experienced all over the world. Kidney diseases are linked to high economic burden, deaths, and morbidity rates. The great importance of collecting a large quantity of health-related data among human cohorts, what scholars refer to as “big data”, has increasingly been identified, with the establishment of a large group of cohorts and the usage of electronic health records (EHRs) in nephrology and transplantation. These data are valuable, and can potentially be utilized by researchers to advance knowledge in the field. Furthermore, progress in big data is stimulating the flourishing of artificial intelligence (AI), which is an excellent tool for handling, and subsequently processing, a great amount of data and may be applied to highlight more information on the effectiveness of medicine in kidney-related complications for the purpose of more precise phenotype and outcome prediction. In this article, we discuss the advances and challenges in big data, the use of EHRs and AI, with great emphasis on the usage of nephrology and transplantation.

When ESKD complicates cancer screening and cancer treatment

End-stage kidney disease (ESKD) affects the recommended screening, incidence, treatment, and mortality of cancer. Cancer occurring in a patient with ESKD can influence candidacy for kidney transplantation as well as dialysis decision-making and cancer treatment. Certain cancers are more common among ESKD patients, notably, viral-mediated cancers that are associated with human papilloma or hepatitis viruses, and urothelial cancers associated with analgesic and Balkan nephropathies. Solid tumors are not believed to occur more frequently in ESKD patients. The presence of ESKD may confer a higher risk of post-surgical complications as well as mortality. The cost-effectiveness of cancer screening depends upon individual cancer risk and estimated overall survival. The high mortality associated with ESKD argues against routine cancer screening in dialysis patients. Cancer treatment in ESKD may be complicated by the need to avoid, adjust doses of and/or coordinate the timing of administration of imaging contrast, chemotherapy, and immunotherapy with dialysis treatments. There is a general dearth of information on the treatment of cancer in ESKD patients. These issues will be discussed, and some general guidelines presented based upon the current literature.

Hsa_circ_0035483 sponges hsa-miR-335 to promote the gemcitabine-resistance of human renal cancer cells by autophagy regulation

Renal clear cell carcinoma (RCC) is the most common pathological type of renal carcinoma and drug resistance often occurs. We studied the effect of hsa_circ_0035483 on gemcitabine sensitivity in RCC, and explored its regulatory effect on downstream hsa-miR-335 and Cyclin B1 (CCNB1). High-throughput sequencing was used to analyze the differentially expressed circRNA in RCC. The expressions of hsa_circ_0035483, hsa-miR-335, CCNB1, and autophagy-related proteins were detected by RT-PCR or Western blot. The target relationships were revealed by RNA pulldown assay and dual luciferase report assay. Autophagy marker LC3 was detected by immunofluorescence. Cell viability was detected by MTT assay. Hsa_circ_0035483 can facilitate gemcitabine-induced autophagy, and enhance the resistance of RCC to gemcitabine. Hsa-miR-335 is the target regulatory point of hsa_circ_0035483. In addition, hsa_circ_0035483 promotes autophagy and tumor growth and enhances gemcitabine resistance in RCC by regulating hsa-miR-335/CCNB1, and silenced hsa_circ_0035483 can enhance gemcitabine sensitivity in vivo. Hsa_circ_0035483 may be the target of gemcitabine resistance in the treatment of RCC.