Topographic modification of the extracellular matrix precedes the onset of bladder cancer

•Using clinical samples of urothelial carcinoma and paired non-neoplastic tissue, we identified a progressive increase of the re-arrangement of the collagen fibers topography from the beginning of the inflammatory process to the tumor onset and invasion.•In two preclinical models, we demonstrated that the re-arrangement of the topography of the collagen fibers created a ground that favors the onset of the tumor. Findings from this study are exploitable for identifying bladder areas at risk of tumor relapse.•Additionally, this study opens avenues for the intravesical instillation of adjuvant therapy that targets enzymes responsible for the linearization of collagen fibers. Non-muscle invasive bladder cancer (NMIBC) patients are affected by a high risk of recurrence. The topography of collagen fibers represents a hallmark of the neoplastic extracellular microenvironment. Assess the topographic change associated with different stages of bladder cancer (from neoplastic lesions to bona fide tumor) and whether those changes favour the development of NMIBC. Seventy-one clinical samples of urothelial carcinoma at different stages were used. Topographic changes preceding tumor onset and progression were evaluated in the rat bladder cancer model induced by nitrosamine (BBN), a bladder-specific carcinogen. The preclinical model of actinic cystitis was also used in combination with BBN. Validated hematoxylin-eosin sections were used to assess the topography of collagen fibrils associated with pre-tumoral steps, NMIBC, and MIBC. Linearization of collagen fibers was higher in Cis and Ta vs. dysplastic urothelium, further increased in T1 and greatest in T2 tumors. In the BBN preclinical model, an increase in the linearization of collagen fibers was established since the beginning of inflammation, such as the onset of atypia of a non-univocal nature and dysplasia, and further increased in the presence of the tumor. Linearization of collagen fibers in the model of actinic cystitis was associated with earlier onset of BBN-induced tumor. The topographic modification of the extracellular microenvironment occurs during the inflammatory processes preceding and favoring the onset of bladder cancer. The topographic reconfiguration of the stroma could represent a marker for identifying and treating the non-neoplastic tissue susceptible to tumor recurrence.