The genetic alterations in the oncogenic pathway of transitional cell carcinoma of the bladder and its prognostic value.

This review focuses on the main oncogenes studied in transitional cell carcinoma (TCC) in order to describe their mechanisms of action and investigate their possible prognostic value. Each oncogene family is reported following the order through which the proliferative signal is transduced from the extracellular space via a growth factor to the nucleus where transcription factors are switched on. Oncogenic activation at any level of the pathway will cause an increased transcription of genes enhancing the cell cycle, and proliferation will therefore be amplified. The main molecular or immunohistochemical studies from the literature on the aberrant expression of these genes are examined and compared with the aid of tables. Conclusions suggest that, although some may initially appear promising, no oncogene, has thus far been found to have a definite prognostic value superior to conventional grading and staging.