[Relationship between pesticide exposure and low-grade superficial bladder urothelial carcinoma]

Few studies have been published analyzing the association between pesticides use and the increased risk of developing urothelial cancer of the bladder (UCB). The aim of this work was to investigate, in a geographical area with a high prevalence of UCB (Axarquia, Malaga province, southern Spain) if a) subjects with occupational exposure to pesticides have greater risk of developing UCB and b) there are histopathological differences with regard to UCB in patients without any exposure.

Case control study. During two years (1994-1996) 96 cases of UCB were included. The histologic grade and the depth of the invasion as well as the associated inflammatory infiltrate were analyzed. A questionnaire was answered by the patients.

58.3% of the case group were working with or had history of exposure to pesticides, compared to 40.6% in the control group (OR = 2.04; 95% CI, 1.1-3.6). The risk increased with a greater time of exposure. In exposed subjects, low grade tumors (OR = 2.6; 95% CI, 1.3-5.2) as well as superficial tumors (OR = 2.3; 95% CI, 1.2-4.4) were more frequent. They were more frequently accompanied by a chronic inflammatory infiltrate (OR = 4.5; 95% CI, 1.8-11.1).

The subjects with occupational exposure to pesticide have greater risk of developing UCB, which is directly proportional to the exposure time. In comparison with the population in the zone without exposure, patients who use pesticides present low grade UCB and less invasive tumors more frequently. These facts were not modified when they were adjusted for tobacco consumption. Exposed patients have UCB with chronic (moderate) inflammatory reaction more frequently than the tumors in non-exposed subjects.