Environmental exposome study for prostate cancer in elderly men from Western China: preliminary findings from a case-control study in the WeEndPd cohort.

OBJECTIVES

To investigate the association between exposure to specific endocrine-disrupting chemicals (EDCs), air pollutants and the risk of localised prostate cancer (PCa) and to evaluate the combined effect of mixed EDC exposures.

DESIGN

A case-control study.

SETTING

Secondary care; a single tertiary hospital in Western China.

PARTICIPANTS

A total of 580 patients with histologically confirmed localised PCa who underwent radical prostatectomy between May 2021 and June 2023 were included as cases. They were matched 1:2 with 1160 cancer-free controls from the same cohort on age (±5 years) and date of biological sample collection. Key exclusion criteria were a history of other malignancies, androgen deprivation therapy prior to surgery or acute urinary infection.

PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the odds of PCa associated with individual and mixed exposures. Primary exposures were urinary concentrations of nine bisphenols (BPs) and nine phthalate metabolites (quantified via high-performance liquid chromatography-tandem mass spectrometry) and estimated ambient air pollution exposure (sulphur dioxide (SO2) and PM₂.₅) based on geocoded residential addresses.

RESULTS

A total of 580 cases and 1160 controls were included in the final analysis. Exposure to the highest quartile of sulphur dioxide (SO2) over 5 years (9.37-28.79 µg/m3) was significantly associated with PCa, yielding an OR of 1.65 (95% CI 1.08 to 2.72; p<0.001) compared with the lowest quartile (3.61-6.89 µg/m3). Urinary concentrations of multiple phthalate metabolites (MECPP, MEHHP and MEHP) and BPs (bisphenol A (BPA) and BPZ) were significantly higher in cases (all p<0.05). Weighted quantile sum (WQS) regression analysis demonstrated a significant positive association between the mixture of EDCs and PCa risk (WQS OR=1.26, 95% CI 1.20 to 1.33; p<0.001).

CONCLUSIONS

Exposure to SO2 and specific EDCs (both individually and as a mixture) is significantly associated with localised PCa.

TRIAL REGISTRATION NUMBER: ChiCTR1900024623.