Current status of chemoradiotherapy for gastric cancer in Japan.

Chemoradiotherapy (CRT) is the latest modality to be explored as a treatment for gastric cancer. Advances have been made in the United States with CRT as preoperative or postoperative adjuvant treatment. The rationale for preoperative or postoperative adjuvant CRT is to increase the curability of surgery or to prevent local recurrence, because standard surgery (D0 or D1) is not sufficient to control local relapse and improve survival where disease has become advanced. D2 is standard in Japan and D2 gastrectomy plus postoperative adjuvant chemotherapy with S-1 is currently standard for stage II and III cancer. Predominant recurrence patterns associated with these advanced disease stages are peritoneal dissemination and hematogenous metastasis. Local relapse or regional nodal recurrence is infrequent. CRT has been provided at only a limited number of institutions in Japan. The response to and safety of CRT for gastric cancer, in combination with various chemotherapeutic agents, are currently being studied in patients with unresectable or recurrent disease. Considering the high response rate, CRT seems to be an attractive option. In the near future, an examination will be made to ascertain whether neoadjuvant CRT in combination with extensive surgery has survival benefits in the treatment of locally advanced disease. Prior to this, a phase I/II study should be conducted in patients with unresectable or recurrent disease.