Protein Expression Profiles among Lichen Sclerosus Urethral Strictures-Can Urethroplasty Success be Predicted?

ABSTRACT

PURPOSE: Urethroplasty of lichen sclerosus strictures has a significantly higher failure rate than strictures due to other causes. We sought to determine predictors of urethroplasty failure in men with lichen sclerosus urethral stricture disease by evaluating protein expression profiles. MATERIALS AND METHODS: Urethral tissue was excised from patients with lichen sclerosus who were undergoing urethroplasty of urethral stricture disease at a single institution. A tissue microarray was created with cores from each sample. Immunohistochemistry was performed to compare protein expression related to inflammation, cell cycle disruption, oxidative stress, hormone receptor status and infection. Stricture recurrence was defined by the need for a subsequent unanticipated procedure for urethral stricture disease. RESULTS: We evaluated 50 men with lichen sclerosus urethral stricture disease, including 31 with successful reconstruction and 19 with recurrent stricture. Recurrent strictures expressed lower levels of several inflammatory markers and had a lower Ki-67 mitotic index and significantly higher vascular endothelial growth factor levels than nonrecurrent strictures. CONCLUSIONS: To our knowledge this is the first study to use tissue protein expression to identify risk factors for urethroplasty failure among men with lichen sclerosus urethral stricture disease. Our findings suggest that recurrent lichen sclerosus strictures demonstrate a suppressed inflammatory response, a decreased cell turnover rate, and poor oxygenation and nutrient delivery. Prospective studies are needed to clarify the role of these pathways in the pathophysiology of lichen sclerosus urethral stricture disease, determine whether preoperative biopsy can predict urethroplasty success, help counsel patients and develop future treatments.