Molecular subtypes of urothelial carcinomas of the bladder in young patients

Urothelial carcinomas in young patients are characterized by specifi c clinical and morphological and genetic features in contrast to their counterparts in elderly patients. Molecular profi ling of tumors in 56 patients under 45 years has been performed using the method of Swedish researchers from the Lund University, the molecular classifi cation of the Lundgroup of researchers using immunophenotyping has been adapted to the cohort of young patients for the fi rst time and clear reproducibility of urothelial carcinoma molecular subtypes occurring in the elderly group of patients has been demonstrated. The urothelial-like A subtype of bladder cancer (78%, p = 0.005), which is associated with an early pathological stage, a favorable prognosis, and the best survival rate, was found to signifi cantly predominate in young patients. Within the urothelial-like subtype, a specifi c tumor variant (so-called CK5/6+/p16+) (7%) was identifi ed, differing in immunophenotypic and clinical features, tending to a more aggressive biological behavior and probably refl ecting a different progression pathway of some urothelial carcinomas in contrast to the elderly patients. The frequency of adverse subtypes (urothelial-like B, genomically unstable, basal/squamous cell-like, mesenchymal-like) in the young group was not more than 6%; their occurrence in patients over 30 years of age with an age-proportional dependence was noted. The performed molecular profi ling of bladder cancer in young patients showed its diagnostic signifi cance, possibility of prognostic stratifi cation and, therefore, reasonable practicality.