The objective of this project is to determine in a non-invasive manner (fecal samples) the predictive value of the intestinal microbiota and the presence of genotoxin-producing bacteria on the response to neoadjuvant treatment in rectal cancer. This could lead to a better understanding and selection of patients for personalized treatment in rectal cancer.
Rectal cancer is the 8th leading cause of cancer in the world with more than 300,000 deaths in 2018. In addition to surgery, neoadjuvant treatment has proven its value in reducing local recurrences. Evaluation of the response to neoadjuvant treatment (essential for the subsequent therapeutic decision but also for the oncological prognosis. It is based on rectal magnetic resonance imaging, completed after surgery by anatomopathology. A personalised treatment with therapeutic de-escalation or intensification for aggressive tumours can be decided depending on the response to Neoadjuvant treatment. Thus, knowledge of the predictive factors of response to neoadjuvant treatment would permit to anticipate and adapt care. The intestinal microbiota is a true microbial organ, playing a major role in maintaining intestinal homeostasis. Some bacterial species have been identified and suspected of playing a role in colorectal carcinogenesis. Among these species, genotoxin-producing Escherichia coli (CPEC) strains such as colibactin (cyclomodulin encoded by the genomic islet pks) are preferentially detected in patients with colorectal cancer (CRC), especially the most aggressive forms. Recent studies show that the intestinal microbiota is a prognostic factor in the response to certain chemotherapies or immunotherapies, but little work has been done on its potential influence on the effectiveness of radiotherapy. This suggests the possibility of using these biomarkers associated with response to neoadjuvant treatment. The objective of this project is to determine in a non-invasive manner (fecal samples) the predictive value of the intestinal microbiota and the presence of genotoxin-producing bacteria on the response to neoadjuvant treatment in rectal cancer. This could lead to a better understanding and selection of patients for tailored treatment in rectal cancer.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
OTHER
Fecal samples collected at different times : during inclusion consultation with surgeon, after neoadjuvant treatment and before surgery.
Institut régional du Cancer de Montpellier
Montpellier, Hérault, France
RECRUITINGCHU Clermont-Ferrand
Clermont-Ferrand, Puy De Dôme, France
NOT_YET_RECRUITINGThe ratio between the proportions of poor response to neoadjuvant treatment in populations so-called "exposed" (patients colonized by bacteria producing toxins (cyclomodulin) and unexposed (patients not colonized by bacteria producing toxins)
Time frame: About 1 years
Change of cyclomodulin-Producing Escherichia Coli colonization rate before and after neoadjuvant treatment
Time frame: About 1 years
Change of cyclomodulin-Producing Escherichia Coli prevalence before and after neoadjuvant treatment
Time frame: About 1 years
Change of prevalence forming the overall bacterial composition before and after neoadjuvant treatment
Time frame: About 1 years
Change of colonization rate (in addition to cyclomodulin-Producing Escherichia Coli) forming the overall bacterial composition before and after neoadjuvant treatment
Time frame: About 1 years
Relative risk of poor response to neoadjuvant treatment in colonized patients with other bacteria ("exposed") compared to non-colonized patients ("unexposed")
Time frame: About 1 years
Proportion of patients colonized according to the modality of the clinical variable age
Time frame: About 1 years
Proportion of patients colonized according to the modality of the clinical variable gender
Time frame: About 1 years
Proportion of patients colonized according to the modality of the clinical variable body mass index
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Masking
NONE
Enrollment
220
Time frame: About 1 years
Overall survival in colonized people by the different types of bacteria that form the overall bacterial composition (including cyclomodulin-Producing Escherichia Coli) compared to non-colonized people
Time frame: About 1 years
Disease-free survival in colonized people by the different types of bacteria that form the overall bacterial composition (including cyclomodulin-Producing Escherichia Coli) compared to non-colonized people
Time frame: About 1 years
Specific survival in colonized people by the different types of bacteria that form the overall bacterial composition (including cyclomodulin-Producing Escherichia Coli) compared to non-colonized people
Time frame: About 1 years
Types of other bacteria forming the overall bacterial composition before neoadjuvant treatment
Time frame: About 1 years