Diagnosis and kidney-sparing treatments for upper tract urothelial carcinoma: state of the art.

Abstract

Conservative management of upper tract urothelial cancer (UTUC) is becoming increasingly popular: the key to success is correct selection of patients with low-risk UTUC based on size (≤2 cm), focality (single lesion), stage (< T2), and grade (low grade). Despite the recent growing interest in the conservative approach to UTUC, the diagnostic process is still a challenge, and kidney-sparing surgery (KSS) is traditionally reserved for patients with contraindications to radical nephroureterectomy. In order to explore the "state of the art" in the diagnosis and conservative treatment of UTUC, a systematic review of the literature was performed. A PubMed, Scopus, and Cochrane search for peer-reviewed studies was performed using the keywords "upper tract urothelial carcinoma" OR "UTUC" OR "upper urinary tract" AND "biopsy" OR "diagnosis" OR "endomicroscopy" OR "imaging" AND "URS" OR "ureteroscopy" OR "kidney-sparing surgery" OR "laser ablation" OR "ureterectomy". We considered as relevant comparative prospective studies (randomized, quasi-randomized, no randomized), retrospective studies, meta-analyses, systematic reviews, and case report series written in the English language. Letters to the editor and contributions written in languages other than English were not considered of value for this review. Eligible articles were reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria. Two hundred and sixty-three (263) records were identified using the above-mentioned keywords. Overall, 30 studies were considered relevant for the purpose of this systematic review and for the evidence evaluation process during qualitative synthesis. The outcomes evaluated in this review were the current diagnostic methods and the KSS approaches in UTUC. Furthermore, we included in the review the emerging technology for distinguishing between normal tissue, low-grade UTUC, and high-grade UTUC. Conclusive diagnosis is fundamental to the decision-making process in patients who could benefit from conservative treatment of UTUC. The most relevant diagnostic modalities are computed tomography urography, local urine cytology, and ureteroscopy with acquisition of an adequate biopsy sample for histology. KSS includes the endourological approach and segmental ureterectomy. Promising technology in the endourological management of UTUC helps in providing intraoperative information on UTUC grading and staging, with a high accuracy. Patients treated conservatively have to undergo stringent postoperative follow-up in order to detect and, if necessary, treat any recurrence promptly. Further larger and multicenter studies are needed to confirm these findings.