Purpose: We identified premalignant lesions in tumor-surrounding histologically normal bladder mucosa from patients with superficial and muscle-invasive bladder cancer to look for "premalignant" lesions as the source of tumor recurrence.
Materials and methods: Tumor-associated antigen expression in histologically normal bladder mucosa in 23 patients with superficial bladder cancer was studied. Histologically normal bladder specimens from 21 patients with muscle-invasive bladder cancer and from 30 prostatic cancer patients served as controls. Tumor-related antigens 486p 3/12, LBS8, 19A211 and M344 were mapped quantitatively with monoclonal antibodies and immunohistological techniques.
Results: Expression of all four bladder tumor-associated antigens was significantly enhanced and more than two antigens were expressed simultaneously in histologically normal mucosa from both bladder-cancer groups, compared with histologically normal bladder mucosa of prostatic carcinoma patients (p < 0.05).
Conclusions: The results suggest the existence of early malignantly transformed cells in the benign-looking and morphologically normal bladder mucosa of superficial bladder carcinoma patients, which possibly is the source of recurrent bladder cancer. This approach models the mapping of histopathologic premalignant lesions of the bladder to predict risk.