LAUSR

We read with interest the paper by M. Lawless et al. very recently published in Histopathology (Stalk versus base invasion in pT1 papillary cancers of the bladder: improved substaging system predicting the risk of progression) (1). The Authors divided tumors into base-focal and base-extensive cases, relying on the criterion of whether or not there was a single focus <1 mm in size (i.e. 20x PF), thus confirming the threshold adopted in our study on pT1 bladder urothelial carcinoma (2), kindly quoted by M. Lawless et al.. This size enabled patient stratification in terms of risk of progression in both studies (1,2), and in others too (3), underscoring the value of T1 substaging recently emerging from a broad meta-analysis (4). This article is protected by copyright. All rights reserved.