Câncer de próstata e exposição a agrotóxicos no Estado de Mato Grosso do Sul

Abstract

Introduction: Investigations about the association between prostate cancer and environmental and/or occupational exposure to pesticides have revealed a possible role of these agents on tumor etiology, but their results are not consistent, in order to permit the establishment of a casual association. A series of studies conducted on Brazil’s Midwest region have shown environmental and human contamination by several pesticides. Objective: This thesis aims to analyze factors associated to prostate cancer incidence and mortality of residents of Mato Grosso do Sul. Material and Methods: The thesis was elaborated in a four articles format. The first one is a literature review to examine the evidences of an association between pesticides exposure and prostate cancer. The bibliographic research was conducted on MEDLINE/PubMed, SCielo and Lilacs databases, using “pesticides” and “prostate cancer” as descriptors, with 08.28.12 as the deadline. On the second article, the trends of mortality from prostate cancer in the Midwest region of Brazil were analyzed for the period 1980-2011. On the third article, the correlations between mortality rates for prostate cancer (2005-2009) and variables related to agricultural production, to the use of health services and socio-demographic information among the Brazilian states were explored, through univariate and multivariate spatial analysis. The fourth article is a hospital- based case-control study, that analyzed the association between prostate cancer and environmental and occupational exposures to pesticides on men living in Mato Grosso do Sul (MS). Individuals residing in MS who had performed prostate biopsy or other outpatient diagnostic procedure of high-complexity on the period of March 2012 to January 201 were eligible for the study. The study population consisted of 316 cases and 326 controls. Data, collected through interviews, included socioeconomic information and life style, nutritional and food consumption variables, besides occupational and environmental exposures to pesticides. The statistical analysis consisted of the estimation of odds ratios (OR) and 95% confidence intervals thorough logistic regression technic. Results: Among the 46 observational analytical studies included in this sistematic review, in 31 of them a positive association between prostate cancer and pesticide exposure or working activities related to agriculture was demonstrated. The four-year average rate of prostate cancer mortality went from 7.65/100000 on the period 1980-83 to 1 4.36/100000 on the last quadrennial of the study, which is above the Brazilian average. In this analysis, the variable tons of produced soybeans presented association with the rates of mortality from prostate cancer (p = 0.030). The variables "living on the countryside from the age of 20" [OR 5.08 (1.95-13.19)] and "home next to a plantation" [OR 2.05 (1.18-3.05)], “prostate cancer family [OR: 2,24 (1,39-3,61)], “body mass index” [OR: 0,96 (0,92-1,00)] e “smoking history” [OR: 0,56 (0,38-3,61) were associated with prostate cancer even after the adjustment by age and by other variables that remained on the final model. Conclusions: The scientific literature suggests that there is a high risk of developing prostate cancer among individuals exposed to pesticides or with work activities related to agriculture. Considered on their whole, the results of the four studies that composed this thesis show a possible association between pesticide exposure and prostate cancer in men living in Mato Grosso do Sul.