[Adjuvant therapy for advanced gastric cancer]

The importance of surgery (gastrectomy plus lymph node dissection) for the treatment of advanced gastric cancer is unquestionable, although there has been a disparity in methods used to achieve local control in Asia and the West. The superiority of D2 dissection has not been confirmed in a large multiinstitutional trial, and the long-term follow-up results of a Dutch trial revealed that the recurrence rate was lower in the D2 group. Thus, the European Society for Medical Oncology and the US National Comprehensive Cancer Network guidelines recommend D2 dissection, leading to a worldwide consensus. Meanwhile, the focus of oncology should be on multimodality treatment for cure, and numerous large, randomized clinical trials have established effective adjuvant treatment. In gastric cancer, different evidence emerged first in the USA, followed by Europe, and Japan/the Republic of Korea to become the standard for each: adjuvant chemoradiation, perioperative adjuvant chemotherapy, and postoperative chemotherapy, respectively. The Japanese standard has become adjuvant S-1 chemotherapy for 1 year after surgery, and the optimal regimen for stage III should be further investigated in consideration of other robust results. Other issues include the role of surgery in local control with regard to adjuvant treatment such as radiation and molecular-targeted treatment to establish a worldwide standard.