Molecular biological changes in bladder cancer.

A large number of potential molecular markers of bladder cancer have been identified, although only a few are truly independent prognostic factors. A number of markers may need to be measured in a single tumour and used as a combination for use in the diagnosis and prognosis of transitional cell carcinoma (TCC). Epidermal growth factor receptor immunoreactivity has been shown to be an independent predictor of survival and stage progression. TP53 may be an independent predictor of recurrence and overall survival in TCC confined to the bladder, and TP53 alterations may predict chemosensitivity in patients who have had TCC treated by radical cystectomy. At present molecular techniques such as fluorescence in situ hybridization and the polymerase chain reaction are restricted to the laboratory, but immunohistochemical methods are available in most hospital pathology departments. There are some discrepancies and conflicting reports of the usefulness of molecular markers in different studies, and these need to be addressed in large, prospective, multi-institutional studies using standardized molecular techniques.