Introduction/Background Phthalates are endocrine-disrupting chemicals (EDCs) widely used in consumer products. They can competitively bind to oestrogen and androgen receptors and impact signalling. In-vitro studies have shown certain phthalates to cause considerable inflammatory reaction. Analysis of EC cell lines exposure indicates butyl-benzyl phthalate (BBP) to influence transcription and miRNA expression. Certain phthalates, such as dibutyl phthalate (DBP) have also been directly associated with increased EC risk. Common small phthalate esters (diethyl phthalate (DEP) and DBP were evaluated in this study to examine the association of exposure to phthalates with EC risk profiles.

Methodology A prospective, single-centre, cohort study including all women diagnosed with EC between December 2020 and February 2022. Patients were asked to provide a urine sample, peripheral venous blood sample as well as complete a lifestyle questionnaire before management. Gas chromatography-mass spectrometry (GC-MS) was used to detect phthalates. All results were adjusted for urinary dilution by measuring urinary creatinine levels.

Results Thirty-nine women with a median age 60 (range 35–86) were included in this study. 29 women (74%) were diagnosed at FIGO I or II stage of the disease, while others were diagnosed at advanced stage. Women were stratified based on clinical features into risk-profiles according to the ESGO-ESTRO-ESP guidelines. DEP was detectable in 24 (75%) of urine samples, DBP was detectable in 31 (97%) samples. Median levels of DEP in urine were 22.8 µg/L (range 4 – 54 µg/L) and 74.9 µg/L (range 23 – 166 µg/L) for DBP. Clinical risk assessment was significantly correlated with DEP r=9.475; p<.050, but not with DBP expression levels r=5.573; p>.233.

Conclusion Exposure to higher concentrations of DEP may be associated with increased biological aggressiveness of EC. If these findings are confirmed in other EC populations, this could influence counselling and management of women with EC.