Role of triazine herbicides in the etiology of epithelial ovarian cancer in the Central Valley of California

This study evaluates the role of the common triazine herbicides as a cause of ovarian cancer in the intensely agricultural and multi-ethnic population of the Central Valley of California. Two studies have shown elevated ovarian cancer risk in women with possible or definite exposure to triazine herbicides (Donna et al., 1984; Donna et al., 1989).; The primary research objectives of this study were to determine if women with ovarian cancer have increased exposure to triazine herbicides; and to determine if the California Department of Pesticide Regulation Pesticide Usage Database (PUD) is a feasible method of constructing exposure profiles. The study also examines the dose-response relationship between triazine herbicide exposure and ovarian cancer risk; and evaluates the triazine ovarian cancer relationship in subsets of the total study population.; The study design is a population-based case-control study of newly diagnosed ovarian cancer cases and random digit dialed control subjects. Both cases and controls were administered the same in-depth, telephone interview. Exposure-disease associations were evaluated using both stratified analysis and logistic regression modeling techniques.; A job exposure matrix was successfully constructed using the questionnaire information and the California Pesticide Use Database. This study showed that it is feasible to construct exposure estimates from these job exposure matrices. The results were robust showing similar results when job weightings were varied.; The main analysis of ever vs. never exposure to any triazines showed that cases were slightly but not significantly more likely to be exposed to triazines than controls (OR = 1.43; 95% CI: 0.77–2.64). Although this estimate does not show a statistically significant association between triazine exposure and ovarian cancer, there is the suggestion of a possible weak association. Examination of residential exposure to triazine herbicides showed no association between residential exposure (as ascertained by residential history near crops) and ovarian cancer (OR = 0.84; 95% CI: 0.54–1.32). Considered with previous studies and animal laboratory data, the evidence at this point is simply not persuasive as to the presence or absence of a causal association between ovarian cancer and triazine exposure.