Can adjuvant chemoradiotherapy replace extended lymph node dissection in gastric cancer?

Abstract

Surgical resection remains the essential part in the curative treatment of gastric cancer. However, with surgery only, long-term survival is poor (5-year survival <25 % in Europe). Randomized studies, which compared limited (D1) lymph node dissection with more extended (D2) resections in the Western world, failed to show a survival benefit for more extensive surgery. A substantial increase in survival was found with perioperative chemotherapy in the MAGIC study. In addition, the SWOG/Intergroup 0116 study showed that postoperative chemoradiotherapy (CRT) prolonged 5-year overall survival compared to surgery only. However, it has been argued that surgical undertreatment undermined survival in this trial. In a randomized Korean study, patients with advanced stage gastric cancer who received postoperative CRT had better outcome after a D2 dissection. At our institute phase I-II studies with adjuvant cisplatin and capecitabine-based CRT have been performed in over 120 patients with resected gastric cancer. Retrospective comparison of patients treated in these studies with those that had surgery only in the D1D2 study, demonstrated that postoperative CRT was associated with better outcome, especially after D1 or a R1 resection. For daily practice, it remains unclear whether patients after optimal (D2) gastric surgery will benefit from postoperative CRT. This is currently being tested in prospective randomized phase III trials (CRITICS; TOPGEAR).