Focal Ablative Therapy for Renal Cell Carcinoma in Transplant Allograft Kidneys. Urology. 2019;125:118-122. [PMID: 30552936 DOI: 10.1016/j.urology.2018.12.003]

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.

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.

Irreversible electroporation in renal tumours: A systematic review of safety and early oncological outcomes

We review the safety and early oncological outcomes of irreversible electroporation (IRE), a novel non-thermal ablation technique, in small renal masses (SRMs). Following PROSPERO registration (CRD42020197943), a systematic search of MEDLINE, EMBASE and SCOPUS databases according to PRISMA guidelines was performed. Critical appraisal of the included studies was performed using the Newcastle-Ottawa Scale. Of 224 articles screened, 10 met the inclusion criteria. In total, 83 patients were identified. Except for one cohort study (n = 41), the remaining studies were case series of n < 10. Follow up was <12 months in 7/10 articles (range 3–34 months). About 10/10 articles reported safety outcomes. There were no 30-day mortalities. The most frequently reported adverse events were transient haematuria (11/83) and asymptomatic perirenal haematomas (7/83). About 62/63 patients with reported length of stay were discharged within 24 h. No significant long-term changes in renal function were reported. About 7/10 articles reported oncological outcomes. Only one article assessed histopathological outcomes, whilst the remaining studies used cross-sectional imaging modalities to assess efficacy, recurrence or disease progression. About 4/7 patients with histopathology outcomes, showed complete response (CR). About 43/55 patients with radiological outcomes showed CR. No mortalities were reported due to SRMs. These initial findings support IRE as safe and feasible in managing SRMs. However, results from larger studies with longer follow-up are needed to evaluate oncological outcomes and compare these with other ablation methods.

[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.

Management of the kidney transplant patient with Cancer: Report from a Multidisciplinary Consensus Conference

INTRODUCTION

Cancer is the second most common cause of mortality and morbidity in Kidney Transplant Recipients (KTRs). Immunosuppression can influence the efficacy of cancer treatment and modification of the immunosuppressive regimen may restore anti-neoplastic immune responses improving oncologic prognosis. However, patients and transplant physicians are usually reluctant to modify immunosuppression, fearing rejection and potential graft loss. Due to the lack of extensive and recognised data supporting how to manage the immunosuppressive therapy in KTRs, in the context of immunotherapy, chemotherapy, radiotherapy and loco-regional treatments, a Consensus Conference was organised under the auspices of the European Society of Organ Transplantation and the Italian Society of Organ Transplantation. The conference involved a multidisciplinary group of transplant experts in the field across Europe.

METHODS

The overall process included a) the formulation of 12 specific questions based on the PICO methodology, b) systematic literature review and summary for experts for each question, c) a two-day conference celebration and the collection of experts' agreements. The conference was articulated in three sessions: "Immunosuppressive therapy and immunotherapy", "Systemic therapy", "Integrated Therapy", while the final experts' agreement was collected with a televoting procedure and defined according to the majority criterion.

RESULTS

Twenty-six European experts attended the conference and expressed their vote. A total of 14 statements were finally elaborated and voted. Strong agreement was found for ten statements, moderate agreement for two, moderate disagreement for one and uncertainty for the last one.

CONCLUSIONS

The consensus statements provide guidance to transplant physicians caring for kidney transplant recipients with cancer and indicate key aspects that need to be addressed by future clinical research.

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.

Transchondral access for irreversible electroporation of hepatocellular carcinoma

Ablative treatment for hepatocellular carcinoma is standard of care in selected settings and is endorsed by international societal guidelines. Centrally located hepatocellular carcinoma are difficult to treat due to their proximity to vasculature and central bile ducts. Irreversible electroporation is a nonthermal ablation modality that has been shown to preserve the extracellular matrix and is less likely to damage structures such as bile ducts and is not susceptible to vascular heat sink. Successful irreversible electroporation requires the parallel placement of probes which can be prevented by ribs or the sternum. This case report describes the use of the coaxial bone biopsy system to enable transchondral access and facilitate parallel placement of probes during irreversible electroporation IRE for the treatment of hepatocellular carcinoma.

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.

Microwave Ablation of Renal Cell Carcinoma of the Transplanted Kidney: Two Cases

Thermal ablative techniques have been increasingly recognized as a valuable alternative to graftectomy and nephron-sparing surgery for the treatment of small neoplasms arising in the transplanted kidney. However, long-term efficacy and safety data are still lacking. In particular, current experience with microwave ablation is limited to a very recent single-centre series of three cases. We herein report two microwave ablations of renal cell carcinoma of the kidney allograft. The procedures were successfully performed under ultrasound guidance with complete tumour necrosis, no peri-operative complications, and preserved renal function. No recurrences were observed after 3 years of follow-up.