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Item does not contain fulltext PURPOSE: Despite being one of the most important clinical outcomes in nonmuscle invasive bladder cancer, there is currently no standard definition of disease progression. Major clinical trials and meta-analyses have used varying definitions or have failed to define this end point altogether. A standard definition of nonmuscle invasive bladder cancer progression as determined by reproducible and reliable procedures is needed. We examine current definitions of nonmuscle invasive bladder cancer progression, and propose a new definition that will be more clinically useful in determining patient prognosis and comparing treatment options. MATERIALS AND METHODS: The IBCG (International Bladder Cancer Group) analyzed published clinical trials and meta-analyses that examined nonmuscle invasive bladder cancer progression as of December 2012. The limitations of the definitions of progression used in these trials were considered, as were additional parameters associated with the advancement of nonmuscle invasive bladder cancer. RESULTS: The most commonly used definition of nonmuscle invasive bladder cancer progression is an increase in stage from nonmuscle invasive to muscle invasive disease. Although this definition is clinically important, it fails to include other important parameters of advancing disease such as progression to lamina propria invasion and increase in grade. CONCLUSIONS: The IBCG proposes the definition of nonmuscle invasive bladder cancer progression as an increase in T stage from CIS or Ta to T1 (lamina propria invasion), development of T2 or greater or lymph node (N+) disease or distant metastasis (M1), or an increase in grade from low to high. Investigators should consider the use of this new definition to help standardize protocols and improve the reporting of progression.

We are in agreement with Lamm et al regarding the need for a new standard definition to describe progression of nonmuscle invasive bladder cancer (NMIBC). We, too, recognized that defining a state of progression before the development of muscle invasion would be a useful tool for clinical trials of patients with NMIBC. Consequently in 2005 we went through a similar process when writing the protocol for the West Midlands (United Kingdom) Bladder Cancer Prognosis Programme (BCPP, incorporating SELENIB [Selenium and Vitamin E Trial in Non-Muscle Invasive Bladder Cancer]), defining progression as “a recurrence with an increase in tumor grade from 1/2 to grade 3, or an increase in TNM stage, or the new occurrence of carcinoma in situ (CIS) in a bladder previously free from such lesions, or the new occurrence of multiple tumors following resection of a solitary tumor, or the need for a cystectomy because of refractory disease.”1 Clearly there are many similarities between our definition of progression for the purposes of BCPP/SELENIB and that proposed by Lamm et al, and we support their rationale and endeavor.