Percutaneous ultrasound-guided radiofrequency ablation of an allograft renal cell carcinoma: a case report

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 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.

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.

High-Intensity Focused Ultrasonography and Radiofrequency Ablation of Renal Cell Carcinoma Arisen in Transplanted Kidneys: Single-Center Experience With Long-Term Follow-Up and Review of Literature

The purpose of this article is to retrospectively evaluate the long-term outcome of patients treated with percutaneous thermoablation for renal cell carcinomas that have arisen in kidney grafts. Between April 2008 and February 2011, we treated 3 patients with renal cell carcinoma on a transplanted kidney: 2 cases were treated with high-intensity focused ultrasonography and 1 patient with radio frequency ablation. Postprocedural ultrasonography did not reveal any complications, and contrast-enhanced ultrasonography showed an avascular area in the treated nodules. None of the patients had recurrent tumors during a long-term clinical and radiologic follow-up (81, 73, and 43 months, respectively).

Renal cell carcinoma in renal allograft: Case series and review of literature

Renal cell carcinoma (RCC) in transplanted kidneys has been reported sporadically with incidence of about 0.5%. There are currently no standard guidelines on the management of allograft RCC in renal transplant recipients. Our objective was to study effectiveness of nephron-sparing surgery (NSS) for allograft RCC. We performed a retrospective analysis of patients with RCC in renal allografts managed with NSS in our institution from January 2000 to December 2015. Patient demographics, interval between transplant and RCC diagnosis, operative parameters, perioperative complications, final pathology, and renal function were evaluated. Three females underwent successful NSS for allograft RCC. Cause of end-stage renal disease was IgA nephropathy in all; mean time between renal transplant and diagnosis of RCC was 23 years. We were able to stay extraperitoneal in all the cases. In the final pathology, two had papillary and one had clear cell RCC. One patient developed pyelocutaneous fistula which was managed by stenting. Long-term functional outcomes of NSS are excellent; none of our patients is dialysis dependent.

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.

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 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.

Management of renal masses in transplant allografts at an Australian kidney-pancreas transplant unit

BACKGROUND

A shift towards partial nephrectomy (PN) in the management of small renal cell carcinoma (RCC) in recent years has prompted a parallel change in the management of rare cases of transplant allograft RCC. There are currently no guidelines on the management of allograft RCC. We present our center experience and review the latest evidence for management of RCC in renal transplant allografts.

METHODS

We performed a retrospective review of the transplant patient registry of a kidney-pancreas transplant center between 1984 and 2012. All confirmed allograft kidney RCC cases were included in this series. MEDLINE search of current literature on renal allograft RCC and selection of appropriate studies were conducted.

RESULTS

A total of 1,241 patients had received either a living, cadaveric, or combined kidney-pancreas transplant at our center, and four cases of allograft RCC were identified. The first case underwent a radical nephrectomy given the central location of the tumor and his young age. The second case underwent an open PN in the setting of a central tumor with minimal morbidity. The third case involved multiple renal lesions that were subsequently treated with radiofrequency ablation (RFA). The fourth case underwent a non-ischemic open PN in the setting of a midpole tumor with minimal morbidity. There have been no cases of local recurrence or metastatic progression at median 21.5 months' follow-up.

CONCLUSION

We have shown the safety and efficacy of minimally invasive techniques such as PN and RFA in a variety of tumors. We consider PN as an appropriate therapy for localized, clinical T1 allograft RCC tumors.

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

Renal cell carcinoma (RCC) is more common in renal transplant and dialysis patients than the general population. However, RCC in transplanted kidneys is rare, and treatment has previously consisted of nephrectomy with a return to dialysis. There has been recent interest in nephron-sparing procedures as a treatment option for RCC in allograft kidneys in an effort to retain allograft function. Four patients with RCC in allograft kidneys were treated with nephrectomy, partial nephrectomy, or radiofrequency ablation. All of the patients are without evidence of recurrence of RCC after treatment. We found nephron-sparing procedures to be reasonable initial options in managing incidental RCCs diagnosed in functioning allografts to maintain an improved quality of life and avoid immediate dialysis compared with radical nephrectomy of a functioning allograft. However, in non-functioning renal allografts, radical nephrectomy may allow for a higher chance of cure without the loss of transplant function. Consequently, radical nephrectomy should be utilized whenever the allograft is non-functioning and the patient's surgical risk is not prohibitive.