CLINICAL ANALYSIS OF PATIENTS WITH OCCUPATIONAL UROTHELIAL TUMORS

Abstract

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 alfa-naphthylamine. No urothelial tumor occurred in the workers exposed to beta-naphythlamine.
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 baldder 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.
The 5, 10, 20 year-survival rates were 92%, 72% and 47%, respectively. Three out of eight cancer death patients died from double cancer. Malignant tumors in other organs than the urinary tract developed in 5.7% in the dyestuff workers. It is indicated that close observation is necessary for dyestuff workers.