Radiochemotherapy With and Without Dose Escalation in Patients Presenting Locally Advanced or Inoperable Carcinoma of the Oesophagus (CONCORDE)

Exclusive concomitant radiochemotherapy (RCT) at a dose of 50 Gy delivered over 5 weeks, according to the RTOG 85-01 protocol, has led to improved 5-year survival in 25% of patients, whereas no patients survived for 5 years using radiotherapy alone for patients with esophageal cancer. Surgery, even when combined with preoperative RCT, also gives disappointing results for locally advanced tumors, which casts serious doubts on the usefulness of preoperative radiotherapy. By varying the fractionation schedule, the length of treatment or the radiotherapy volumes, it has become possible to obtain levels of loco-regional relapse of around 35 to 45%. After reviewing the results for loco-regional relapse according to the dose of radiation and the recommended radiotherapy volumes, we aimed to investigate why increasing the dose of radiation has no impact in esophageal cancers. Although INT-0123 phase III trial showed no benefit of dose escalation in esophageal cancer, some issues remain unclear as most of the patients who died in the experimental arm were treated above 50Gy. Moreover, only the tumor was treated up to 64Gy while involved nodes were not considered for dose escalation in this trial. In the RTOG 85-01phase III trial, an elective nodal irradiation from subclavicular fossa up to the esophagogastric junction was performed with a 2D technique, delivering 30Gy which could be considered as not appropriate.

In this randomized phase II/III trial, we aim to test an exclusive concomitant chemoradiotherapy for patients with non resectable esophageal cancer with a dose escalation up to 66Gy on the primary tumor as well as the involved nodes using a 3D conformal technique combined with a 40 Gy elective nodal irradiation on lymph node stations (as defined by the RTOG) with a risk of microscopic involvement ≥ 20%.