Prognostic importance of specific immunoreactivity in occupational bladder cancer.

Sixty-eight workers with a history of exposure to a bladder carcinogen were followed up to see whether changes in lymphocyte immunoreactivity to a bladder-cancer-cell target were predictive of the development of neoplasia of the urothelium. A twofold or greater increase in reactivity was strongly associated with the development of abnormal urinary cytology suggestive or indicative of malignant change. Changes in immunoreactivity to a non-bladder-cancer-cell target did not have this association. The findings support the possibility that changes in lymphocyte immunoreactivity may be used to predict the onset of bladder cancer in people exposed to bladder carcinogens.