Therefore, better efficacy cannot be achieved via surgery alone, which results in promotion of adjuvant chemoradiotherapy. In America, it has been accepted as a standard treatment contributing to the improved overall survival rates compared with surgery alone. Benefits of the treatment have also been proved in European studies. However, adjuvant chemoradiotherapy is not indicated for 21%-35% patients due to its high postoperative complication rates and worse recovery. Additionally, postoperative chemoradiotherapy would delay the initial time of intensified chemotherapy, along with the difficulty in target volume delineation and low tolerance doses of organs at risk.