Project

Esophageal and esogastric junction cancer is the 7th leading cause of cancer-related deaths worldwide, and the incidence of adenocarcinoma is steadily increasing in developed countries. Neoadjuvant treatment (NT) including perioperative chemotherapy or neoadjuvant chemoradiotherapy followed by surgery is the standard treatment for these tumors. Despite recent advances, their prognosis remains poor. Previous studies have shown that patients who respond well to NT have better overall survival. It is necessary to study the underlying mechanisms responsible for resistance to NT, attributed to a complex interaction between gene regulation and environmental factors. The gut microbiota has received considerable attention in recent years due to its association with the initiation and progression of many gastrointestinal cancers. An emerging approach is to consider the impact of gut microbiota on the efficacy of antitumor therapies. To date, very few clinical studies have investigated the influence of gut microbiota on the response to NT in esophageal and esogastric junction adenocarcinoma. The objective of our study is to determine the predictive value of intra and peritumoral microbiota on the response to NT in esophageal and esogastric adenocarcinoma. This is a retrospective study conducted using available tumor samples from the French Clinico-Biological Database of Esogastric Cancers (FREGAT). The primary objective is to investigate a correlation between the response to NT and the composition of intra(péri)tumoral microbiota. The analysis of intra(péri)tumoral microbiota composition will be performed on tumor samples obtained from pre-therapeutic biopsies and from the surgical specimen (post-NT). The study will include 102 patients enrolled at Lille University Hospital. The results could ultimately allow for personalized therapeutic management based on the intra(péri)tumoral bacterial signature and the development of non-invasive biomarkers to predict treatment response.