[Nine cases of bladder cancer occurring in occupational dye users].

Workers in the dye manufacturing industry have a high risk of urinary bladder cancer. There may also be a high relative risk of bladder cancer in occupational dye users. Nine occupational dye users were found to have bladder cancer. The period of engaging with dye work ranged from 5 to 40 years. Seven patients had bladder cancer and the other 2 patients had lesions both in the bladder and in the renal pelvis. Histopathology of all cases was transitional cell carcinoma. Three cases were classified into grade 1 and 6 cases into grade 2. One patient died of bladder cancer. The other 8 patients are alive. Four cases recurred after TUR therapy. It is necessary to establish systemic mass screening examination of occupational dye users for the early diagnosis of bladder cancer.