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

Renal Cell Carcinoma in End-Stage Kidney Disease and the Role of Transplantation

Kidney transplant patients have a higher risk of renal cell carcinoma (RCC) compared to non-transplanted end-stage kidney disease (ESKD) patients. This increased risk has largely been associated with the use of immunosuppression; however, recent genetic research highlights the significance of tissue specificity in cancer driver genes. The implication of tissue specificity becomes more obscure when addressing transplant patients, as two distinct metabolic environments are present within one individual. The oncogenic potential of donor renal tissue is largely unknown but assumed to pose minimal risk to the kidney transplant recipient (KTR). Our review challenges this notion by examining how donor and recipient microenvironments impact a transplant recipient's associated risk of renal cell carcinoma. In doing so, we attempt to encapsulate how ESKD-RCC and KTR-RCC differ in their incidence, pathogenesis, outcome, and approach to management.

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.

Renal Doppler Ultrasound in the Evaluation of Renal Function in Patients with Sepsis

This study was aimed to explore the renal Doppler ultrasound in the evaluation of renal function in patients with sepsis. Fifty patients with sepsis or septic shock were classified into the acute kidney injury (AKI) group (n =25) and the non-AKI group (n =25) according to whether they had AKI. The measurements of renal resistance index (RRI) and power Doppler ultrasound (PDU) were performed on all patients within 7 days of admission to the intensive care unit (ICU). The patient's renal function was assessed. The results showed that the RRI of the two groups showed a slight upward trend over time, and the RRI of the AKI group was higher than that of the non-AKI group. After 7 days in AKI group, the areas under the receiver operating characteristic (ROC) curves of RRI were 0.745, 0.683, 0.729, 0.856, 0.793, 0.819, and 0.836 (P <0.05). There were no statistically considerable differences in areas under ROC curves between the two groups (P >0.05). The grouping of AKI and the time were both fixed effects, and the individual patients were randomized effects. Besides, the linear models were statistically analyzed. The results showed that the differences between the two groups were statistically insignificant (P >0.05). There was no significant difference in the PDU scores measured at different times within 7 days after ICU admission between the two groups (P >0.05). In conclusion, renal Doppler ultrasound had a good adoption effect in the evaluation of the renal function of patients with severe sepsis, which is worth promoting in clinical practice.

Renal Cell Carcinoma and Kidney Transplantation: A Narrative Review

Kidney transplant recipients (KTRs) are at increased risk of developing renal cell carcinoma (RCC). The cancer can be encountered at different steps in the transplant process. RCC found during work-up of a transplant candidate needs treatment and to limit the risk of recurrence usually a mandatory observation period before transplantation is recommended. An observation period may be omitted for candidates with incidentally discovered and excised small RCCs (<3 cm). Likewise, RCC in the donor organ may not always preclude usage if tumor is small (<2 to 4 cm) and removed with clear margins before transplantation. After transplantation, 90% of RCCs are detected in the native kidneys, particularly if acquired cystic kidney disease has developed during prolonged dialysis. Screening for RCC after transplantation has not been found cost-effective. Treatment of RCC in KTRs poses challenges with adjustments of immunosuppression and oncologic treatments. For localized RCC, excision or nephrectomy is often curative. For metastatic RCC, recent landmark trials in the nontransplanted population demonstrate that immunotherapy combinations improve survival. Dedicated trials in KTRs are lacking. Case series on immune checkpoint inhibitors in solid organ recipients with a range of cancer types indicate partial or complete tumor response in approximately one-third of the patients at the cost of rejection developing in ~40%.

[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.

Image-Guided Thermal Ablation in De Novo Renal Tumor Arising in Kidney Allograft: 3-Year Follow-Up. A Case Report

De novo tumors in renal allograft recipients are a severe complication during long-term follow-up after transplantation and may require transplantectomy. Herein we present a case of de novo renal tumor arising in the renal allograft, treated with the less invasive image-guided radiofrequency ablation (RFA) with long-term follow-up. A tumor was detected during the routine annual follow-up in a patient with good renal function who underwent renal transplantation in 1989. Computed tomography (CT) showed a mass in the allograft whose shape, vascularization, and density suggested the presence of a solid, malignant mass, located in the upper renal pole, that measured 17 mm. CT-guided RFA was performed successfully, and the outcome was verified by an immediate control CT after the intervention. No residual pathologic tissue, major bleeding, or damage to the adjacent parenchyma was evidenced. The patient was discharged with stable renal function. CT scan and ultrasound were performed 3, 6, 12, 18, 24, and 36 months after RFA. No signs of change in renal function, recurrence, neovascularization, or damage to the adjacent microcirculation were observed during the 3-year follow-up. In conclusion, percutaneous RFA of small renal tumors occurring in renal allografts can be considered a function-sparing, safe, and effective therapeutic option when difficult surgical removal may be anticipated. Our experience also supports the need for yearly renal allograft ultrasound follow-up for early identification of small neoplasm than can be treated less invasively.

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.