Treatment options for renal cell carcinoma in renal allografts: a case series from a single institution

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.

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.

Treatment of allograft renal cell carcinoma with partial nephrectomy in a pediatric kidney transplant

Renal cell carcinoma (RCC) is a common malignancy among kidney transplant recipients that often occurs in the native kidney. The incidence of RCC in the renal allograft is rare and carries the double risk of returning to dialysis and the development of metastatic cancer. The majority of reported cases of RCC in transplanted kidneys are in adult recipients and its occurrence in the pediatric age group is an uncommon event. There are currently no established guidelines on the treatment of RCC in transplant recipients.

We report our experience of a 15-year-old male who developed allograft RCC 12 years later after transplantation. MRI confirmed the presence of the mass near the hilum of the renal allograft and biopsy revealed a Papillary Renal Cell Carcinoma (PRCC) type I. A partial allograft nephrectomy was successfully performed with negative tumor margins. The patient’s serum creatinine 12 months post-operation was 1.9 mg/dL and presently he has no evidence of residual disease, recurrence, or metastasis.

Partial nephrectomy is an effective treatment option for renal allograft RCC as it spares the patient from returning to dialysis until retransplantation is possible and necessary.

[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.

Transplant Radical Nephrectomy and Transplant Radical Nephroureterectomy for Renal Cancer: Postoperative and Survival Outcomes

BACKGROUND The treatment of complex tumors in non-functioning renal transplants requiring surgical extirpation is challenging. Here, we report the largest series of patients who underwent transplant radical nephrectomy for renal cell carcinoma (RCC) and transplant radical nephroureterectomy for urothelial cell carcinoma (UCC) in their transplanted kidneys. MATERIAL AND METHODS From 2004 to 2018, 10 patients underwent transplant radical nephrectomy (7 patients) and nephroureterectomy (3 patients). Retrospective analyses, in terms of complications, oncological recurrence, and survival, of peri-operative and long-term outcomes, were performed. RESULTS Out of the 10 patients, 7 had RCC and 3 had UCC. No intraoperative mortality occurred. Three patients presented with Clavien-Dindo grade IIIa or greater within 30 days of surgery. Two patients died within 60 days of surgery, both due to vascular events: one due to myocardial infarction and one due to stroke. Two other patients died: one after 2.9 years, due to myocardial infarction, and the other after 6 years, due to unknown reasons. At the 7-year follow-up, there was a 60% overall survival rate. For all patients, average survival post-nephrectomy was approximately 4.5 years, including the 6 living patients and 4 deceased patients. Importantly, there was no observed cancer recurrence. CONCLUSIONS This study reports outcomes of the largest series of transplant radical nephrectomy and nephroureterectomy for malignancies of renal allografts. In the optimized setting, extirpative surgeries appear safe, with favorable long-term oncological and survival outcomes.

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.

De novo renal carcinoma arising in non-functional kidney graft: a national retrospective study

AIM

Characteristics of renal carcinoma arising in non-functional graft in renal transplant recipients (RTR) are unknown. We studied a large national retrospective cohort to analyze circumstances of diagnosis, treatment and outcome compared to the literature.

METHODS

Study included all RTR presenting with kidney graft tumors irrespective of the histology, except those with lymphoma and including those tumors arising in non-functional renal graft. Between January 1988 and December 2018, 56,806 patients had renal transplantation in the 32 centers participating in this study. Among this cohort, 18 renal graft tumors were diagnosed in non-functional grafts.

RESULTS

The median patient age at the time of diagnosis was 42.1 years (31.7-51.3). Median age of kidney grafts at the time of diagnosis was 56.4 (23.2-63.4). Eight (44.4%) tumors were discovered fortuitously on renal graft histologic analysis. Fourteen tumors (77.8%) were papillary carcinomas. Two patients had clear cell carcinomas and one patient had a pTa high-grade multifocal urothelial carcinoma in the graft of the upper tract with an in situ carcinoma.

CONCLUSION

Renal carcinomas in non-functional grafts are rare entities and most of them are diagnosed fortuitously. Despite the fact that these tumors are small, low grade and with a good prognosis, regular monitoring of non-functional grafts should be performed with at least an annual ultrasonography.

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.

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.

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.

Renal Cell Carcinoma Arising From Renal Allograft Detected by 18F-FDG PET-CT

Renal cell carcinoma arising from renal allograft is a rare condition. A 56-year-old man with a history of 3 renal transplantation due to renal failure presented poor appetite and weight loss for 3 months. Possibility of tumor of unknown origin was suspected. For this reason, an FDG PET/CT was performed, and the images showed a hypermetabolic focus in the lower pole of the left renal transplant, suggestive of a malignant lesion. Subsequent pathological examination following allograft nephrectomy confirmed grade 4 renal cell carcinoma.

Donor Kidney With Renal Cell Carcinoma Successfully Treated With Radiofrequency Ablation: A Case Report

BACKGROUND

The risk of donor-transmitted cancer is evident.

CASE REPORT

We report the case of a 69-year-old woman who was transplanted with a kidney from a deceased donor. Four days after transplantation a routine ultrasound scan revealed a 3-cm tumor in the middle-upper pole of the allograft. A biopsy showed the tumor to be papillary renal cell carcinoma. The patient was treated with radiofrequency ablation. This procedure was complicated by the development of a cutaneous fistula and open surgery was done with resection of an area of necrosis in the kidney and of the fistula. The maintenance immunosuppressive regimen was modified with a change in treatment to everolimus in combination with reduced dose mycophenolate and low-dose steroids. The patient was followed for 4.5 years and during that time she remained dialysis independent with an excellent allograft function (serum creatinine, 95 μmol/L [1.04 mg/dL]).

CONCLUSIONS

To the best of our knowledge, this is the first case in which a donor-transmitted tumor was diagnosed in the renal allograft only 4 days after transplantation and subsequently treated successfully with radiofrequency ablation.

Renal cell carcinoma in kidney allografts: histologic types, including biphasic papillary carcinoma

Kidney transplant recipients are at increased risk for malignancy, with about 5% incidence of cancer in native end-stage kidneys. Carcinoma in the renal allograft is far less common. Prior studies have demonstrated a propensity for renal cell carcinomas (RCCs) of papillary subtypes in end-stage kidneys, and perhaps in allograft kidneys, but most allograft studies lack detailed pathologic review and predate the current classification system. We reviewed our experience with renal carcinoma in kidney allografts at 2 academic centers applying the International Society of Urological Pathology classification, informed by immunohistochemistry. The incidence of renal allograft carcinoma was about 0.26% in our population. Of 12 allograft carcinomas, 6 were papillary (50%), 4 were clear cell (33%), 1 was clear cell (tubulo)papillary, and 1 chromophobe. Two of the papillary carcinomas had distinctive biphasic glomeruloid architecture matching the newly named "biphasic squamoid alveolar" pattern and were difficult to classify on core biopsies. The 2 cell types had different immunophenotypes in our hands (eosinophilic cells: RCC-/CK34betaE12+ weight keratin +/cyclin D1+; clear cells: RCC+/cytokeratin high molecular weight negative to weak/cyclin D1-). None of the patients experienced cancer recurrences or metastasis. Our study confirms the predilection for papillary RCCs in kidney allografts and highlights the occurrence of rare morphologic variants. Larger studies are needed with careful pathologic review, which has been lacking in the literature.

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.

Nephron-saving surgery for abscess of renal allograft using radiofrequency bipolar sealer

Thousands of patients with renal disease are on waiting lists for kidney transplant. Survival and quality of life on hemodialysis are much lower than that after renal transplantation. Renal allografts are extremely valuable and worth saving at all costs. Many complications can be seen after organ transplants on short and long term as rejection, vascular compromise, and infection. There are various reports on partial nephrectomy after renal transplant secondary to de novo masses in the renal allograft. Here, we present a case where we used radiofrequency bipolar sealer for partial nephrectomy for necrotic abscess of the renal allograft. We successfully saved the allograft with partial nephrectomy despite parenchymal infection and necrosis.