Postoperative adjuvant chemoradiotherapy in D2-dissected gastric cancer: is radiotherapy necessary after D2-dissection?

Studies from the Far East have demonstrated that D2-dissection is superior to D0/1-dissection. The effect of postoperative chemoradiotherapy (CRT) after D2-dissection has not been accepted due to the lack of D2-dissection in Western countries, as well as the potential harmful effect of radiotherapy. In the current NCCN guideline, adjuvant chemotherapy alone is recommended in D2-dissected patients. However, three recent prospective randomized controlled trials in South Korea and China (ARTIST, NCC and Multicenter IMRT Trials) demonstrated that adjuvant CRT can be safely administered to D2-dissected patients with notable benefits. To identify the role of radiotherapy (RT) in the D2-dissected postoperative setting, clinical research attempts should include (1) identification of high-risk patients for loco-regional recurrence who might benefit from CRT; (2) modification of RT target volume based on the findings that failure patterns should be different after D1- and D2-dissection; and (3) integration of new RT techniques to decrease treatment-related toxicity. The present paper is a review of recent studies addressing these fields. Well-designed prospective randomized studies are needed to clearly define the role of adjuvant CRT in D2-dissected gastric cancer, however, future clinical studies should also focus on answering these questions.