Urinary glyphosate concentration and breast cancer risk: a case-control study in Santa Fe, Argentina

DONÁ F; LORENZ V; RICARDO T; REPETTI MR; DEMONTE LD; MILESI MM; VARAYOUD J

Mar del Plata

Congreso; LXVII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2022

SAIC

Pesticide exposure has been associated with higher breast cancer (BC) risk. Glyphosate (GLY) is the most widely used pesticide worldwide and has been classified as a 2A “probable human carcinogen” by the International Agency for Research on Cancer. Since human exposures to GLY are rising rapidly and may also increase BC risk, we determined the urinary concentration of GLY and its degradation product, aminomethylphosphonic acid (AMPA) and we designed a case-control study to determine if residence or other lifestyle/medical factors could be associated with the BC risk. We analyzed 130 women (35 BC cases and 95 controls) who attended the gynecology service of J.M. Cullen Hospital in Santa Fe. Demographic data, lifestyle factors and residence were obtained by questionnaire. Medical outcomes and reproductive history were abstracted from medical records. We collected urine from 74 women (17 BC cases and 57 controls). Urine concentrations of GLY and AMPA were assessed by Ultra high performance liquid chromatography–Mass spectrometry. GLY was detected in 92.8% of urine samples (mean 0.48 µg/L, range 0.10-3.50 µg/L), and no differences were observed between cases and controls groups. AMPA was not detected in any of the analyzed samples. We found an association between increased risk of BC with older women (OR: 1.12, 95% CI: 1.06-1.18), older age at first delivery (OR: 1.18, 95% CI: 1.04-1.34) and residence near agricultural fields (OR: 9.36, 95% CI: 2.8-30.4). To our knowledge, this is the first study examining the urinary concentration of GLY in Argentina, indicating the ubiquitous presence of the pesticide in human samples. The novelty of the detection of GLY in urine, provides baseline information that is relevant for designing future decisions. In addition, our preliminary findings suggest an increased BC risk associated with the place of residence; however, these results require confirmation in a larger population to increase the power of the study.