Upper Urinary Tract Carcinoma In Situ: Current Knowledge, Future Direction

Abstract

Purpose: Carcinoma in situ of the urinary tract is a high grade form of nonmuscle invasive urothelial cancer. Our understanding of this entity in the upper tract is poor, and case management remains challenging due to knowledge gaps regarding the definition, diagnosis, treatment options and followup of the disease. We reviewed the available literature for similarities and differences between bladder and upper tract carcinoma in situ, and herein summarize the best available data.

Materials and methods: We reviewed PubMed® and MEDLINE™ databases from January 1976 through September 2014. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement was used to screen publications. All authors participated in the development of a consensus definition of disease.

Results: A total of 61 publications were found suitable for this review. All studies were retrospective. Compared to bladder carcinoma in situ, upper tract carcinoma in situ appears to have lower progression rates and improved survival. All available studies demonstrate topical therapy to be effective in treating upper tract carcinoma in situ, with decreased recurrence rates compared to bladder carcinoma in situ. Highlighted areas of current knowledge gaps include variable definitions of disease, methods of drug delivery and ideal treatment course. Improving methods for detection may allow easier diagnosis and more effective treatment.

Conclusions: Based on the available data, organ preserving therapy with topical agents is an alternative to radical surgery in select patients with upper tract carcinoma in situ, although this method has not been evaluated in prospective trials. A paradigm shift regarding detection and treatment is needed to improve care and allow better renal preservation. A consensus definition of the disease is offered, and several areas of major knowledge gaps and opportunities for future research are identified.

Keywords: BCG vaccine; carcinoma in situ; urinary bladder neoplasms; urologic neoplasms.