Systematic Review
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Sep 6, 2019; 7(17): 2487-2504
Published online Sep 6, 2019. doi: 10.12998/wjcc.v7.i17.2487
Systematic review of ablative therapy for the treatment of renal allograft neoplasms
Evaldo Favi, Nicholas Raison, Federico Ambrogi, Serena Delbue, Maria Chiara Clementi, Luca Lamperti, Marta Perego, Matteo Bischeri, Mariano Ferraresso
Evaldo Favi, Maria Chiara Clementi, Luca Lamperti, Marta Perego, Matteo Bischeri, Mariano Ferraresso, Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan 20122, Italy
Nicholas Raison, MRC Centre for Transplantation, King’s College London, London WC2R 2LS, United Kingdom
Federico Ambrogi, Mariano Ferraresso, Department of Clinical Sciences and Community Health, University of Milan, Milan 20122, Italy
Serena Delbue, Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan 20100, Italy
Author contributions: Favi E, data collection, data analysis, data interpretation, drafting the article, critical revision, and final approval; Raison N, drafting the article, language revision, critical revision, and final approval; Ambrogi F, data analysis, data interpretation, drafting the article, critical revision, and final approval; Delbue S, data interpretation, critical revision, and final approval; Clementi MC, data collection, data analysis, editing the article, and final approval; Lamperti L, data interpretation, critical revision, and final approval; Perego M, data collection, data analysis, editing the article, and final approval; Bischeri M, data collection, data analysis, editing the article, and final approval; Ferraresso M, data interpretation, critical revision, and final approval.
Conflict-of-interest statement: The authors do not have any conflicting interests.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Evaldo Favi, MD, PhD, Senior Lecturer, Surgeon, Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza n. 28, Milan 20122, Italy. evaldofavi@gmail.com
Telephone: +39-2-55035603Fax: +39-2-55035630
Received: March 28, 2019
Peer-review started: March 28, 2019
First decision: April 18, 2019
Revised: August 1, 2019
Accepted: August 20, 2019
Article in press: August 20, 2019
Published online: September 6, 2019
Processing time: 162 Days and 21.8 Hours
Abstract
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.

Keywords: Ablative therapy; Cryoablation; Radiofrequency ablation; Microwave ablation; High-intensity focused ultrasonography; Irreversible electroporation; Neoplasm; Kidney transplant; Renal allograft; Systematic review

Core tip: Ablative therapy (AT) is a minimally invasive alternative to radical or partial nephrectomy for the treatment of renal allograft tumours. To date, limited data exist regarding long-term efficacy and safety. We performed a systematic review on radiofrequency ablation, cryoablation, microwave ablation, high-intensity focused ultrasound, and irreversible electroporation of neoplasms arising in the transplanted kidney and described treatment-specific and overall outcomes. In the considered cases, AT was successfully offered to all transplant recipients with benign tumours or with American Joint Committee on Cancer T1a N0 M0 renal cell carcinomas of the kidney allograft who were not suitable for more aggressive and demanding surgical treatments.