Effect of Chemotherapy on Metabolic Flexibility in the Context of Cachexia in Cancers of the Esophagus and Gastroesophageal Junction

Cachexia is a syndrome frequently associated with digestive cancers and more particularly with esophageal and gastroesophageal adenocarcinoma. Its pathophysiology remains poorly understood, multi-factorial, but strongly correlated to the prognosis of patients. It's a consequence of the imbalance of energy balance linked to tumoral process, to dysphagia and to anorexia, frequently present in these cancers. At the center of this imbalance, adipose tissue plays a major role. Recent studies showing that the mobilization of lipid substrates and the hypermetabolism of adipocytes are involving in its development, even before loss of muscle. As part of the management, neoadjuvant chemotherapy is usually administered with the main objective to reduce tumor extension and dissemination through actions on DNA and mitosis. These treatments will also alter the mitochondrial function of cells in other tissues, probably including that of adipocytes. A paradoxical effect on the cachectic process could thus be envisaged, as a decrease in mitochondrial activity and associated hypermetabolism, and therefore a preservation of fat mass, and by extension of muscle mass.

Primary endpoint: identify the adipocyte factors involved in the energy imbalance associated with the cachectic process in patients managed for esophageal or gastroesophageal adenocarcinoma.

Secondary endpoint: compare the results obtained before and after chemotherapy treatment according to the cachectic state and the anatomical location of the adipose sample (subcutaneous versus visceral) to evaluate the resting energy expenditure.