Clinical Research Directory

Confirmation of the Link Between Endocrine Disruptors Exposure and Breast Cancer and Identification of Biological Response Biomarkers

A wide variety of chemicals are constantly being introduced in our environment. The toxicological consequences related to the exposure to these compounds and their impact on public health ar of growing concern. It is now accepted that the occurrence of some non-communicable chronic diseases (diabetes, cancer, cardiovascular diseases…) is the result of complex interactions between environmental factors (chemical, physical and biological) and genetic factors. These non-communicable diseases have significantly increased in recent decades et have become the world's leading cause of deaths. Among these environmental factors, and in particular chemicals, the class of endocrine disruptors (EDs) is of particular concern. EDs are found ubiquitously in our environment. They are found in the natural environment (water, air, soil, etc.) as well as in everyday objects and our food. As a result, the general population is widely exposed to these EDs, which can be measured in a variety of biological media. The collection of biological matrices is essential for studying the exposure of populations to EDs. The choice of biological matrices depends on the physicochemical characteristics of the EDs studied and the type of exposure being assessed. Internal exposure to EDs is most often assessed through blood or urine concentrations in spot samples. Measuring urinary EDs concentrations remains a reference method for biomonitoring bisphenols and parabens. In order to assess long-term exposure to EDs, it was proposed to determine EDs concentrations in hair. In addition to these biological matrices for assessing general short-term and long-term exposure, the use of breast adipose tissue will enable in situ assessment of EDs exposure in the patients included. Moreover, adipose tissue represents an interesting biological matrix for determining exposure to pollutants with short half-lives, such as bisphenols and parabens, particularly when the latter have lipophilic characteristics. In addition, the use of this matrix will enable a non-targeted metabolomics approach to identify possible markers of biological response to EDs exposure, and to determine links between this exposure and carcinogenesis processes.

Effects of Endocrine Disruptors on the Gut Microbiota and Assessment of Their Impact on Colorectal Cancer Development (PERMICA)

Colorectal cancer is the third most common cancer worldwide, yet it was the second leading cause of cancer-related deaths in 2020. The average French population faces a colorectal cancer risk partly linked to lifestyle factors. The majority of colorectal cancer cases (approximately 85%) are not caused by hereditary mutations. Environmental factors, such as lifestyle or diet (notably through endocrine disruptors), can affect the gut microbiota (a collection of microorganisms - bacteria, viruses, parasites, and fungi - residing in the intestinal environment) and lead to disturbances in its composition, referred to as dysbiosis. While the mechanisms underlying dysbiosis associated with colorectal cancer remain poorly understood, the involvement of certain ingested substances, known as xenobiotics, is increasingly suspected, including endocrine disruptors. Among the most common endocrine disruptors found in water and food are parabens and phthalates, which will be examined in detail in this study. These substances may be directly involved in the development of colorectal cancer and in response to its treatment. The main objective of this studie is to characterize the relationship between colorectal cancer diagnosis, activity/composition of the gut microbiota, and patients' exposure to selected endocrine disruptors, particularly parabens and phthalates.