The incidence of occupational urothelial
tumor and the accompanied problems were studied on the workers who had manufactured or handled aromatic
amines at a certain chemical factory. Twenty-five out of 398 dyestuff workers, who were examined at regular intervals, were found to have urothelial
tumors and the incidence rate was 63%. The mean age at onset, the mean period of aromatic exposure and the mean latent period from the initial exposure until
tumor development were 61 year-old, 7.2 years and 30 years, respectively. A high incidence rate was found in the long exposed workers and the smoking group. The negative correlation was observed between the age of first exposure to
carcinogens and the latent period. The workers who had been exposed to two or three kinds of aromatic
amines had the highest incidence followed by those exposed to
benzidine and those to
alpha-naphthylamine. No urothelial
tumor occurred in the workers exposed to
beta-naphthylamine. Ninety-four percent of the initial
tumors were superficial and transurethral resection of
tumors was performed as the initial surgery for the patients with
bladder tumors. The recurrence rate in the bladder cavity after the surgery was 39%, which was almost the same rate as that of non-occupational
bladder tumors, however, the recurrence rate in the upper urinary tract was high (26%). The positive rate in the examination of urine cytology was 60% for initial
tumors, 74% for recurrent
tumors. The urine cytology was a significant method for the detection and monitoring of the patients with occupational urothelial
tumors.(ABSTRACT TRUNCATED AT 250 WORDS)