Abstract PO-125: Prenatal proximity to agricultural use of endocrine-disrupting pesticides and risk of testicular germ cell tumor (TGCT) among Latino and non-Latino adolescents in California

BACKGROUND. Incidence of testicular germ cell tumors (TGCTs) has increased steadily in the United States in recent years, especially among Latinos. TGCT initiation is believed to occur during fetal development and to be related to endocrine disruption; the increasing prevalence of in utero exposures to endocrine- disrupting chemicals may have contributed to the rise in the disease’s incidence. METHODS. This registry-based case-control study included 381 California-born patients diagnosed with TGCT at age 15-19 years from 1997-2011 (336 non- seminomas, 41 seminomas) and 762 controls matched on birth year and race/ethnicity. We assessed the agricultural application of 22 endocrine-disrupting pesticides (EDPs) using California’s Pesticide Use Reporting (PUR) database for an area within a 3km radius of participants’ birth address in the year prior to birth; 15 high-volume EDPs (those to which 50 or more participants were potentially exposed) were included in statistical analyses. We used logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for log2-transformed continuous pesticide levels, and to calculate attributable risk (AR) for dichotomous exposure (zero and low application vs. high application). Analyses accounted for the timing of pesticide application, histologic subtype, race/ethnicity, birth year, and neighborhood socioeconomic status (SES). RESULTS. Overall, 48% of cases and 45% of controls lived within 3km of an EDP application in the year before birth. Nearby pesticide applications were greater among Latinos than non-Latinos for 13 of 15 EDPs; the median [interquartile range (IQR)] for total EDP application was 29 kg [5- 135] vs. 11 kg [1-80]. Application was also greater for those born after 1990 (the period of time with complete PUR reporting) than before 1990 for 14 of 15 EDPs (median [IQR] for total EDP application: 54 kg [10-229] vs. 13 kg [0.7-70]). Analyses of individual EDPs showed an increased risk of TGCT associated with acephate (OR [95%CI]: 1.1 [1.0-1.2] and 1.3 [1.0-1.7] for continuous and binary exposures, respectively). In analyses stratified by ethnicity, risk remained elevated for acephate application among Latinos (n=614, OR [95% CI] for continuous exposure model: 1.1 [1.0-1.2]) and for carbaryl and copper sulfate in non-Latinos (n=504, OR [95% CI]: 1.2 [1.0-1.3] and 1.1 [1.0-1.3], respectively). Overall there were no differences by PUR reporting period (before and after 1990) and application timing (preconception and trimesters), yet risk appeared to be higher for non-seminomas and among high SES participants. The population AR for high levels of acephate was 5.4% among Latinos, and Citation Format: Scott J. Swartz, Libby Morimoto, Todd Whitehead, Robert Gunier, Joseph Wiemels, Xiaomei Ma, Catherine Metayer. Prenatal proximity to agricultural use of endocrine-disrupting pesticides and risk of testicular germ cell tumor (TGCT) among Latino and non-Latino adolescents in California [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-125.