Progress in multidisciplinary treatment for esophageal cancer in Japan as reflected in JCOG studies

摘要

Changes in the standard treatment for esophageal cancer in Japan are reflected in the history of consecutive studies conducted by the Japan Esophageal Oncology Group (JEOG), a subgroup of the Japan Clinical Oncology Group (JCOG). Following the era of preopera-tive radiotherapy in the 1970s, the emphasis in surgical adjuvant therapy shifted from postoperative radiotherapy in the 1980s to postoperative chemotherapy including cis-platin as a key drug in the 1990s. Later, the optimal timing for perioperative adjuvant therapy returned to before surgery based on the results of a JCOG study (JCOG9907) that compared preoperative chemotherapy with postoperative chemotherapy in the late 2000s. Next, the clinical question of which is better, preoperative aggressive chemotherapy or preoperative chemoradiotherapy, still needs to be resolved. Concurrent chemoradiotherapy using cisplatin and 5-fluorouracil became a standard non-surgical treatment for esophageal cancer from the early 1990s onwards. Based on the preferable results of definitive chemoradiotherapy for unresectable advanced disease, definitive chemoradiotherapy was considered to be a possible alternative treatment modality in stage I esophageal cancer patients. Therefore, JEOG conducted a phase III study (JCOG0502) to demonstrate the non-inferiority of chemoradiotherapy compared with surgery in patients with stage I esophageal squamous cell carcinoma. If definitive chemoradiotherapy fails in patients with stage II/III esophageal cancer, salvage surgery is now recommended. Therefore, JEOG has initiated a phase II study (JCOG0909) to evaluate the efficacy and safety of this combined treatment modality.