Nephron sparing surgery for De Novo kidney graft tumor: results from a multicenter national study

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.

Updated National Study of Functional Graft Renal Cell Carcinomas: Are They a Different Entity?

OBJECTIVE

To analyze de novo graft carcinoma characteristics from our updated national multicentric retrospective cohort.

METHODS

Thirty-two transplant centers have retrospectively completed the database. This database concerns all kidney graft tumors including urothelial, and others type but excludes renal lymphomas over 31 years.

RESULTS

One hundred and fifty twokidney graft carcinomas were diagnosed in functional grafts. Among them 130 tumors were Renal Cell Carcinomas. The calculated incidence was 0.18%. Median age of the allograft at diagnosis was 45.4 years old. The median time between transplantation and diagnosis was 147.1 months. 60 tumors were papillary carcinomas and 64 were clear cell carcinomas. Median tumor size was 25 mm. 18, 64, 21 and 1 tumors were respectively Fuhrman grade 1, 2, 3 and 4. Nephron sparing surgery (NSS) was performed on 68 (52.3%) recipients. Ablative therapy was performed in 23 cases (17.7%). Specific survival rate was 96.8%.

CONCLUSION

This study confirmed that renal graft carcinomas are a different entity: with a younger age of diagnosis; a lower stage at diagnosis; a higher incidence of papillary subtypes.

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.

De Novo Malignancies after Kidney Transplantation

Cancer is an important outcome after kidney transplantation because it is the second leading cause of death in most Western countries. The excess risk of cancer after transplantation is approximately two to three times higher than the age- and sex-matched general population, driven largely by viral- and immune-related cancers. Once cancer develops, outcomes are generally poor, particularly for those with melanoma, renal cell carcinoma, and post-transplant lymphoproliferative disease. More importantly, effective screening and treatment strategies are limited in this high-risk population. In this review, we begin with a patient's journey that maps the experience of living with a kidney transplant and understand the patient's knowledge, education, and experience of cancer in the context of transplantation. The epidemiology and burden of cancer in recipients of kidney transplants, along with the up-to-date screening and treatment strategies, are discussed. We also focus on the current understanding of optimal care for recipients of kidney transplants who are living with cancer from the patients' perspectives.

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.

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.

Fluorescence In Situ Hybridization for the Origin of De Novo Renal Cell Carcinoma in a Kidney Allograft: A Case Report

BACKGROUND

We present a rare case of de novo renal cell carcinoma that developed in an allograft kidney 14 years after transplantation.

CASE REPORT

A 39-year-old man underwent living donor kidney transplantation from his mother. After 14 years, routine screening ultrasonography revealed a solid mass of 30-mm diameter in the kidney allograft. Partial nephrectomy was performed by clamping the renal artery under in situ cooling. Tissue histology revealed clear cell carcinoma with negative surgical margins. We explored the tumor's genetic origin using fluorescence in situ hybridization to analyze the X and Y chromosomes of the tumor cells. Postoperative hemodialysis was avoided, and the patient's serum creatinine level remained stable.

CONCLUSIONS

Fluorescence in situ hybridization clearly indicated that the tumor originated from the donor and that the tumor vasculature originated from the recipient. The patient recovered well and remains without any tumor recurrence.

[Renal cell carcinoma of the kidney transplant: The French guidelines from CTAFU]

OBJECTIVE

To propose recommendations for the management of renal cell carcinomas (RCC) of the renal transplant.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU to evaluate prevalence, diagnosis and management of RCC arousing in the renal transplant. References were assessed according to a predefined process to propose recommendations with levels of evidence.

RESULTS

Renal cell carcinomas of the renal transplant affect approximately 0.2% of recipients. Mostly asymptomatic, these tumors are mainly diagnosed on a routine imaging of the renal transplant. Predominant pathology is clear cell carcinomas but papillary carcinomas are more frequent than in general population (up to 40-50%). RCC of the renal transplant is often localized, of low stage and low grade. According to tumor characteristics and renal function, preferred treatment is radical (transplantectomy) or nephron sparing through partial nephrectomy (open or minimally invasive approach) or thermoablation after percutaneous biopsy. Although no robust data support a switch of immunosuppressive regimen, some authors suggest to favor the use of mTOR inhibitors. CTAFU does not recommend a mandatory waiting time after transplantectomy for RCC in candidates for a subsequent renal tranplantation when tumor stage<T3 and low ISUP grade.

CONCLUSION

These French recommendations should contribute to improving the oncological and functional prognosis of renal transplant recipients by improving the management of RCC of the renal transplant.

Treatment options for localised renal cell carcinoma of the transplanted kidney

Currently, there is no consensus among the transplant community about the treatment of renal cell carcinoma (RCC) of the transplanted kidney. Until recently, graftectomy was universally considered the golden standard, regardless of the characteristics of the neoplasm. Due to the encouraging results observed in native kidneys, conservative options such as nephron-sparing surgery (NSS) (enucleation and partial nephrectomy) and ablative therapy (radiofrequency ablation, cryoablation, microwave ablation, high-intensity focused ultrasound, and irreversible electroporation) have been progressively used in carefully selected recipients with early-stage allograft RCC. Available reports show excellent patient survival, optimal oncological outcome, and preserved renal function with acceptable complication rates. Nevertheless, the rarity and the heterogeneity of the disease, the number of options available, and the lack of long-term follow-up data do not allow to adequately define treatment-specific advantages and limitations. The role of active surveillance and immunosuppression management remain also debated. In order to offer a better insight into this difficult topic and to help clinicians choose the best therapy for their patients, we performed and extensive review of the literature. We focused on epidemiology, clinical presentation, diagnostic work up, staging strategies, tumour characteristics, treatment modalities, and follow-up protocols. Our research confirms that both NSS and focal ablation represent a valuable alternative to graftectomy for kidney transplant recipients with American Joint Committee on Cancer stage T1aN0M0 RCC. Data on T1bN0M0 lesions are scarce but suggest extra caution. Properly designed multi-centre prospective clinical trials are warranted.

Management of Renal Cell Carcinoma and Other Renal Masses in the Kidney Graft

PURPOSE OF REVIEW

Renal masses in the kidney graft pose an important clinical dilemma, balancing graft function against the need for cancer control.

RECENT FINDINGS

Donor origin cancers in the renal graft can be classified as 'donor transmitted' or 'donor derived'. The landmark TracerX Renal changed our understanding of renal cell carcinoma oncogenesis, demonstrating that key mutations in childhood lead to clinically apparent tumours in later life. Identified pre-operatively, contemporary evidence suggests that masses excised prior to transplantation result in acceptable oncologic safety and graft function. Identified post-operatively management mirrors that for a mass in a solitary kidney in the non-transplant population, with focus on a nephron-sparing approach. With growing number of kidney transplants each year, ageing donors, and increasing graft survival, masses in the renal graft are likely to become a more prevalent clinical conundrum.

Renal cell carcinoma in kidney transplant recipients: descriptive analysis and overview of a major German transplant center

Aim: Elevated risk of malignancy-related death after renal transplantation is reported and renal malignancy was ranked as the third most frequent site of malignancy-related death. However, there is a lack of data characterizing renal cell carcinoma associated with end-stage renal disease and kidney transplantation. Patients & methods: We retrospectively identified 5250 patients who underwent kidney transplantation at the Hannover Medical School since 1970. Results: 124 patients with renal cell carcinoma (incidence 2.36%) were identified. Among all patients, metastatic recurrence was noted in 4.8%. In multivariate analysis, tumor stage and hemoglobin were identified as independent prognostic markers of OS, while tumor grading was predictive for disease recurrence. Conclusion: Apart from showing the prognostic value of tumor staging and hemoglobin, our data suggest that a risk adapted approach for early transplantation is feasible.

Systematic review of ablative therapy for the treatment of renal allograft neoplasms

BACKGROUND

To date, there are no guidelines on the treatment of solid neoplasms in the transplanted kidney. Historically, allograft nephrectomy has been considered the only reasonable option. More recently, nephron-sparing surgery (NSS) and ablative therapy (AT) have been proposed as alternative procedures in selected cases.

AIM

To review outcomes of AT for the treatment of renal allograft tumours.

METHODS

We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 Checklist. PubMed was searched in March 2019 without time restrictions for all papers reporting on radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA), high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE) of solid tumours of the kidney allograft. Only original manuscripts describing actual cases and edited in English were considered. All relevant articles were accessed in full text. Additional searches included all pertinent references. Selected studies were also assessed for methodological quality using a tool based on a modification of the Newcastle Ottawa scale. Data on recipient characteristics, transplant characteristics, disease characteristics, treatment protocols, and treatment outcomes were extracted and analysed. Given the nature and the quality of the studies available (mostly retrospective case reports and small retrospective uncontrolled case series), a descriptive summary was provided.

RESULTS

Twenty-eight relevant studies were selected describing a total of 100 AT procedures in 92 patients. Recipient age at diagnosis ranged from 21 to 71 years whereas time from transplant to diagnosis ranged from 0.1 to 312 mo. Most of the neoplasms were asymptomatic and diagnosed incidentally during imaging carried out for screening purposes or for other clinical reasons. Preferred diagnostic modality was Doppler-ultrasound scan followed by computed tomography scan, and magnetic resonance imaging. Main tumour types were: papillary renal cell carcinoma (RCC) and clear cell RCC. Maximal tumour diameter ranged from 5 to 55 mm. The vast majority of neoplasms were T1a N0 M0 with only 2 lesions staged T1b N0 M0. Neoplasms were managed by RFA (n = 78), CA (n = 15), MWA (n = 3), HIFU (n = 3), and IRE (n = 1). Overall, 3 episodes of primary treatment failure were reported. A single case of recurrence was identified. Follow-up ranged from 1 to 81 mo. No cancer-related deaths were observed. Complication rate was extremely low (mostly < 10%). Graft function remained stable in the majority of recipients. Due to the limited sample size, no clear benefit of a single procedure over the other ones could be demonstrated.

CONCLUSION

AT for renal allograft neoplasms represents a promising alternative to radical nephrectomy and NSS in carefully selected patients. Properly designed clinical trials are needed to validate this therapeutic approach.

Incidence and Mortality of Renal Cell Carcinoma after Kidney Transplantation: A Meta-Analysis

Background: The incidence and mortality of renal cell carcinoma (RCC) after kidney transplantation (KTx) remain unclear. This study’s aims were (1) to investigate the pooled incidence/incidence trends, and (2) to assess the mortality/mortality trends in KTx patients with RCC. Methods: A literature search was conducted using the MEDLINE, EMBASE and Cochrane databases from inception through October 2018. Studies that reported the incidence or mortality of RCC among kidney transplant recipients were included. The pooled incidence and 95% CI were calculated using a random-effect model. The protocol for this meta-analysis is registered with PROSPERO; no. CRD42018108994. Results: A total of 22 observational studies with a total of 320,190 KTx patients were enrolled. Overall, the pooled estimated incidence of RCC after KTx was 0.7% (95% CI: 0.5–0.8%, I² = 93%). While the pooled estimated incidence of de novo RCC in the native kidney was 0.7% (95% CI: 0.6–0.9%, I² = 88%), the pooled estimated incidence of RCC in the allograft kidney was 0.2% (95% CI: 0.1–0.4%, I² = 64%). The pooled estimated mortality rate in KTx recipients with RCC was 15.0% (95% CI: 7.4–28.1%, I² = 80%) at a mean follow-up time of 42 months after RCC diagnosis. While meta-regression analysis showed a significant negative correlation between year of study and incidence of de novo RCC post-KTx (slopes = −0.05, p = 0.01), there were no significant correlations between the year of study and mortality of patients with RCC (p = 0.50). Egger’s regression asymmetry test was performed and showed no publication bias in all analyses. Conclusions: The overall estimated incidence of RCC after KTX was 0.7%. Although there has been a potential decrease in the incidence of RCC post-KTx, mortality in KTx patients with RCC has not decreased over time.

Focal Ablative Therapy for Renal Cell Carcinoma in Transplant Allograft Kidneys

OBJECTIVE

To evaluate outcomes after focal ablative therapy for renal cell carcinoma (RCC) in transplant allograft kidneys.

METHODS

After institutional review board approval, patients with a history of RCC in a transplanted allograft kidney who underwent focal ablative therapy were identified. Complete chart reviews were performed and the relevant data were extracted for cumulative analysis.

RESULTS

Six patients were treated with focal ablative therapy for RCC in a transplanted allograft kidney at our institutional between 2010 and 2017. Masses were diagnosed at a median of 8 years (range 1 month-8 years) after transplantation. Median mass size was 3 cm. Three patients were treated with microwave ablation, 1 with percutaneous irreversible electroporation, 1 with laparoscopic cryoablation, and 1 with open cryoablation. Median follow-up was 45 months (range 8-61 months). The median creatinine level was 1.65 before ablation and 1.58 1 year after ablation. No patients required dialysis after ablation. No patients developed local recurrence during the follow-up period. However, 1 patient developed lymph node metastases 4 years after ablation. Two patients died during follow-up of other causes. At the time of death both patients had functioning grafts.

CONCLUSION

Focal ablative therapies are a feasible, renal-sparing intervention for the management of RCC in renal allografts at intermediate-term follow-up.

Oncocytoma managed by active surveillance in a transplant allograft kidney: a case report

BACKGROUND

The ethical implications of the utilization of kidneys with solid renal masses (SRMs) in transplantation are the subject of lively debate in the transplantation community and beyond. One of such implications is that as the life expectancy of renal transplant patients improve, the prevalence of SRMs in donors is likely to increase. We report a case of an oncocytoma in a renal allograft complicating a deceased-donor kidney transplant.

CASE PRESENTATION

A 60-year-old woman received and underwent deceased-donor renal transplantation for end-stage renal disease after a waiting-list period of 11 years. Kidney Doppler ultrasound (DUS) of the deceased donor was negative for any nodular lesion. The finding of the DUS, done on postoperative day 1, to assess the patency of the graft, was suspicious for an acute arterial thrombosis but did not reveal any focal irregularities. An ensuing computed tomography (CT) scan did not show any arterial complications but serendipitously revealed a 2.4-cm lesion on the upper pole of the renal allograft, which was not detected during the back-table or ultrasonography monitoring. Histology of the biopsied lesion was consistent with oncocytoma. However, because the eosinophilic variant of chromophobe renal cell carcinoma may morphologically resemble renal oncocytoma, immunohistochemical staining was performed. The results were negative, ruling out chromophobe RCC. After discussing the therapeutic options and potential related outcomes with the patient, we found no reason for resection of the lesion or an allograft nephrectomy, given the low risk of malignant transformation in an oncocytoma. Active surveillance of the benign tumor was done with ultrasonography, every 2 months, for the first year and, then, with magnetic resonance imaging, every year. The patient received mycophenolate-mofetil, tacrolimus, and prednisone throughout the 5-year follow-up period, and the regimen for immunosuppression was not changed despite the presence of the renal mass. After 60 months, we report that none of the radiological findings have shown any morphological changes of the lesion, and the patient is well.

CONCLUSION

To the best of our knowledge, we report the first case of an oncocytoma in a renal allograft complicating a deceased-donor kidney transplant, which was successfully managed by active surveillance.

Urologic malignancies in kidney transplantation

With advances in immunosuppression, graft and patient outcomes after kidney transplantation have improved considerably. As a result, long-term complications of transplantation, such as urologic malignancies, have become increasingly important. Kidney transplant recipients, for example, have a 7-fold risk of renal cell carcinoma (RCC) and 3-fold risk of urothelial carcinoma (UC) compared with the general population. While extrapolation of data from the general population suggest that routine cancer screening in transplant recipients would allow for earlier diagnosis and management of these potentially lethal malignancies, currently there is no consensus for posttransplantation RCC or UC screening as supporting data are limited. Further understanding of risk factors, presentation, optimal management of, and screening for urologic malignancies in kidney transplant patients is warranted, and as such, this review will focus on the incidence, surveillance, and treatment of urologic malignancies in kidney transplant recipients.

Solid Renal Masses in Transplanted Allograft Kidneys: A Closer Look at the Epidemiology and Management

The objective of this review is to explore the available literature on solid renal masses (SRMs) in transplant allograft kidneys to better understand the epidemiology and management of these tumors. A literature review using PubMed was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology. Fifty-six relevant studies were identified from 1988 to 2015. A total of 174 SRMs in 163 patients were identified, with a mean tumor size of 2.75 cm (range 0.5-9.0 cm). Tumor histology was available for 164 (94.3%) tumors: clear cell renal cell carcinoma (RCC; 45.7%), papillary RCC (42.1%), chromophobe RCC (3%), and others (9.1%). Tumors were managed by partial nephrectomy (67.5%), radical nephrectomy (19.4%), percutaneous radiofrequency ablation (10.4%), and percutaneous cryoablation (2.4%). Of the 131 patients (80.3%) who underwent nephron-sparing interventions, 10 (7.6%) returned to dialysis and eight (6.1%) developed tumor recurrence over a mean follow-up of 2.85 years. Of the 110 patients (67.5%) who underwent partial nephrectomy, 3.6% developed a local recurrence during a mean follow-up of 3.12 years. The current management of SRMs in allograft kidneys mirrors management in the nontransplant population, with notable findings including an increased rate of papillary RCC and similar recurrence rates after partial nephrectomy in the transplant population despite complex surgical anatomy.

Radiofrequency Ablation of T1a Renal Cell Carcinomas within Renal Transplant Allografts: Oncologic Outcomes and Graft Viability

PURPOSE

To evaluate oncologic outcomes and graft viability after percutaneous radiofrequency (RF) ablation of renal cell carcinoma (RCC) developing within renal transplant allografts.

MATERIALS AND METHODS

A single-institution, retrospective study reviewed all patients treated with RF ablation for RCC between February 2004 and May 2016. Ten patients were identified (age 49.6 y ± 12.6; 9 men, 1 woman) with 12 biopsy-confirmed RCC tumors within the allograft (all T1a, mean diameter 2.0 cm ± 0.7). Mean time from transplant to RCC diagnosis was 13.2 years ± 6.3. RF ablation was performed on an outpatient basis using conscious sedation. Procedural efficacy, complications, oncologic outcomes, and allograft function were evaluated. Statistical analysis with t tests and Pearson correlation compared allograft function before and after RF ablation and impact of proportional ablation size to allograft volume on function after ablation.

RESULTS

Technical success rate and primary technique efficacy were 100% (12/12). No local or distant RCC progression was seen at mean follow-up of 54.3 months ± 38.7 (range, 9-136 months). Graft failure requiring hemodialysis or repeat transplantation occurred in 3 patients (26, 354, and 750 d after RF ablation), all of whom had glomerular filtration rate (GFR) < 30 mL/min/1.73 m² before ablation. For all patients, mean GFR 6 months after RF ablation (35.8 mL/min/1.73 m² ± 17.7) was not significantly different (P = .8) from preprocedure GFR (36.2 mL/min/1.73 m² ± 14.3). Proportional volume of allograft that was ablated did not correlate with immediate or long-term GFR changes. One patient died of unrelated comorbidities 52 months after ablation. No major complications occurred.

CONCLUSIONS

RF ablation of renal allograft RCC provided effective oncologic control without adverse impact on graft viability.

Successful Endovascular Control of Renal Artery in a Transplant Kidney During Nephron Sparing Surgery (NSS) for Large Centrally Located Tumor

Renal cell carcinoma in a transplant kidney is a rare condition. Nephron Sparing Surgery (NSS) is the treatment of choice. One of the main technical challenges is obtaining adequate vascular control. We present a rare case of large centrally located hillar tumor in a kidney 18 years after transplantation treated with NSS. Vascular control was achieved by using a novel approach. Post-operative course was uneventful with minimal decrease in renal function. We believe that this unique choice of treatment can be used in cases of NSS where the access to the renal pedicle is limited.

A national study of kidney graft tumor treatments: Toward ablative therapy

BACKGROUND

Results of the conservative treatment of renal cell carcinomas arising in functional renal transplants are unknown compared to transplant nephrectomy. Only small series or case reports have been reported.

METHODS

Data were collected from 32 transplantation centers nationwide on cases of de novo tumors in functional renal transplants presumed to be malignant between January 1988 and December 2013.

RESULTS

Among 116 de novo transplant tumors, 62 were treated conservatively including: 48 by partial nephrectomy (PN) and 14 by thermal ablation (TA). These patients were compared to 30 other patients who were treated by transplant nephrectomy. The median age of the transplanted kidneys at the time of diagnosis was 43.5 years old as calculated from the donor's age. Tumors treated by transplant nephrectomy presented more often with symptoms (pain, fever, impaired condition, hematuria) than tumors treated conservatively (P = .019). After PN, final histology showed 27 (47.5%) papillary carcinomas, 19 (32.2%) clear cell carcinomas, 1 mixed carcinoma, and 2 oncocytomas. The median tumor size treated by PN was 24 mm with no difference in comparison to the TA group. Nine patients treated by PN had postoperative complications (21%), including 4 requiring operative intervention (Clavien IIIb). None of the patients treated by TA had complications. Specific survival was 100% at the time of last follow-up (median time after treatment 37 months) for patients treated by PN or TA.

CONCLUSION

PN proved to be efficient in the treatment of small tumors of transplanted kidneys with good long-term functional and oncologic outcomes, including avoiding return to dialysis. TA seems to be an alternative therapy with good results in selected patients.

Conservative treatment of de novo renal carcinoma on kidney graft

BACKGROUND

De novo renal carcinoma in kidney transplants is an uncommon but not exceptional condition and is of significant importance due to the potential for recipient mortality and graft loss. The aim of our study was to determine the management and outcome of these tumors in our Kidney Transplantation Unit.

MATERIAL AND METHODS

We analyzed cases of de novo kidney tumors among patients who underwent transplantation in the last 17 years in our Kidney Transplantation Unit. We detected 3 cases of clear cell carcinoma and 1 case of papillary carcinoma on the graft. We conducted follow-up on the tumor and renal function and analyzed patient responses to changes in immunosuppression.

RESULTS

Tumorectomy was performed in all cases, and subsequent transplantectomy was required for patients with papillary carcinoma. None of the patients had relevant surgical complications. We also changed the patients' regimen to a proliferation signal inhibitor or mTOR inhibitor and completely withdrew all anticalcineurin agents. With a mean follow-up of 43.5 months (15-61), the 3 patients with clear cell carcinoma survived with good graft function and with no evidence of tumor recurrence. The patient with papillary carcinoma underwent follow-up at another hospital center.

CONCLUSIONS

Conservative surgery along with conversion to a proliferation signal inhibitor appears to be a safe option for treating primary tumors in kidney grafts and offers good oncological and renal function results in the short and medium term.

[Urological follow-up and development of cancer after renal transplantation]

BACKGROUND

The number of renal transplant recipients is rising, as well as graft and recipient survival. The mainstay of urological follow-up is to ensure urine transport and voiding function; also, the diagnosis and treatment of urological malignancies following renal transplantats is growing in importance. As urological malignancies are one of the three most common tumors following renal transplantation (RT), meticulous and regular urological evaluation is a central part of follow-up care after RT.

RECOMMENDATIONS

Urological evaluation following RT must ensure correct urine transport and voiding function. Transplant ureter strictures, relevant ureteral reflux and voiding dysfuntion (e.g., neurologic dysfunction, benign prostate hypeplasia) must be excluded or treated. Urinary tract infection (UTI), which can be life threatening in the immunosuppressed transplant recipient, must be diagnosed and treated consequently and for an adequate period of time. Prophylaxis of UTIs is indicated in patients with recurrent symptomatic UTI as well as in the initial 6 months following renal transplantation. Asymptomatic bacteriuria must not necessarily be treated. The incidence of urological malignancies like renal cell carcinoma, urothelial cancer of the bladder, and penile carcinoma is increased following RT, while the incidence of prostate and testis cancer is the same as in the nontransplant population. Surgical and nonsurgical treatment options do not differ from the normal population. Adaptation, cessation, or switching of the immunosuppressive regimen in case of urologic malignancy must be decided on the individual recipient basis.

Renal cell carcinoma in functional renal graft: Toward ablative treatments

The occurrence of a kidney transplant tumor is a rare but serious issue with a double risk: the return to dialysis and the development of metastatic cancer. Publications on this topic are mainly case reports. The purpose of this review was to report an exhaustive literature review of functional graft renal cell carcinomas to highlight the impact of tumors on the renal graft outcomes. 201 de novo renal carcinomas in functional renal grafts from 69 publications were included. Incidence was estimated at 0.18%. Graft tumors were mostly asymptomatic (85.9%). Whatever the discovery circumstances of graft tumors, they were mostly documented by graft ultrasounds supplemented by CT-scanning or MR imaging. Nephron sparing surgery (95 patients) was the first treatment performed followed by radiofrequency ablation (38 patients) and cryotherapy (10 patients). The most common tumor graft histology was clear cell carcinoma (46.4%), followed by papillary carcinoma (43.7%). Specific mortality was 2.9% with 6 deaths. Renal graft cell carcinoma is a rare pathology with a low specific death. When possible, conservative treatment should be the first choice.

Successful treatment with sirolimus for an angiomyolipoma mimicking renal cell carcinoma in a transplanted kidney

Angiomyolipoma (AML) is a benign mesenchymal tumor composed of blood vessels, smooth muscle, and mature adipose tissue. AMLs in the kidney allografts are rare. We report a case of AML that was incidentally found 1 year after transplantation. Abdominal computed tomography showed a 4-cm renal tumor with contrast enhancement and an early washout pattern, resembling a renal cell carcinoma. Tumor biopsy proved a lipid-poor AML. Tumor diameter decreased to 2.4 cm after 6 months of treatment with sirolimus. Sirolimus not only reduces tumor size, but also benefits a transplant patient who needs immunosuppression.