Anti-Migration System for Anti-reflux Oeso-gastric Stent (ANTIMIG)

In order to reduce the rate of spontaneous intragastric migration of esophageal stent placed for gastroesophageal junction tumor, anti-migration device has been developed. Pilot studies suggest the absence of morbidity of this device, but no comparative study has been conducted to confirm the interest of this anti-migration device. The aim of this study is to compare the rate of intragastric migration of 2 types of esophageal stents with and without an anti-migration device placed for locally advanced or metastatic malignant stenosis of the gastroesophageal junction. * Main objective: To evaluate the rate of intragastric migration of 2 types of esophageal stents (one with and the second without anti-migration device) placed for malignant stenosis of the gastroesophageal junction. * Secondary objective(s): * Degraded migration rate (M3 and M6) if patient alive, and duration of survival without dysphagia * Comparison of the morbidity of these two stents * Comparison of the effectiveness of these two stents on dysphagia and reflux * Clinical and technical failure rate of these two stents This is a prospective, controlled, randomized, multicentre, single-blind study.