Study Design Considerations when Measuring Exposure Biomarkers of Non-Persistent Endocrine Disruptors in Epidemiologic Studies of Chronic Diseases Including Breast Cancer

摘要

Endocrine disrupting chemicals are believed to increase risk of breast cancer. Exposure to EDCs is challenging to study with environmental biomarkers because they often have short half-lives and their exposure source may be linked to personal products used only during certain seasons, days, or certain times of the day. Designing studies incorporating the exposure biomarkers of these chemicals requires many critical decisions including consideration of the limit of detection (LOD) and quality assurance measures. The toxicokinetics and toxicodynamics of these chemicals likely vary by age and therefore, correlations of the different biomakers available in urine vs. serum may also vary during the different windows of exposure. Benefits versus costs (both financial and non-financial) of repeated measurements over time need to be considered. Other exposure assessment and study design challenges include the content of the consent form, the biomedia to use, the time of sample collection, and laboratory selection. Protocols for sample collection and processing should consider feasibility within the overall study program, acceptability to the study participants, and especially elimination of potential sources of sample contamination. The effort to maintain a complete biospecimen inventory, and to track distribution of biospecimens, is substantial but absolutely necessary. This presentation will review these challenges and provide helpful suggestions for meeting them in design of epidemiologic studies examining exposure to EDCs with periodic use and short half-lives.