当前Ⅳ期胃癌患者实施转化治疗成为了研究热点，它是指技术或肿瘤学上初始不可切除或边界可切除的患者，通过有效化疗后实现R0切除。目前，虽然新化疗药物和分子靶向药物有效改善了Ⅳ期胃癌患者的预后，但是结果仍旧差强人意。通过发展和改善化疗方案， Ⅳ期胃癌患者越来越多的实现了转化治疗。但是，目前尚无Ⅳ期胃癌患者在转化治疗中获益的确凿证据。为明确进展期胃癌患者手术干预的意义，我们对63例行S-1/顺铂或S-1/紫杉醇的Ⅳ期胃癌患进行回顾性分析。结果显示：患者中位生存期(MST)为16.5个月，而S-1/顺铂和S-1/紫杉醇两组MST无统计学差异。其中27例患者实施了胃切除，无严重围手术期并发症发生。对于化疗敏感的患者，行手术切除患者MST有效延长。这表明：对于Ⅳ期胃癌患者，给予S-1基础化疗方案后转化手术安全有效。同时，我们也对Ⅳ期胃癌患者转化手术后辅助化疗的疗效进行研究。行转化手术的Ⅳ期胃癌患者MST为31.2个月，而转化手术后辅助化疗的Ⅳ期胃癌患者MST为12.5月。单药S-1和双药联合患者之间MST无差异。49例患者中36例复发，31例患者接受了转化手术后2线化疗。相较于只接受一线化疗的患者，接受二线治疗患者的无复发生存期更长。总的来说，辅助化疗意义尚需进一步的研究证实。 目前我们正在进行S-1基础化疗后转化治疗的Ⅱ期观察性队列研究。更进一步，在亚洲临床肿瘤学协会(FACO)覆盖的亚洲国家中[包括日本临床肿瘤学会( JSCO)、韩国临床肿瘤学会(KACO)、中国临床肿瘤学会(CSCO)、日本胃癌学会( JGCA)、韩国胃癌协会(KGCA)及中国抗癌协会(CACA)，一项大型回顾和前瞻性队列研究正在进行。
Current situation and issues of conversion therapy for Stage IV gastric cancer
Conversion therapy on stage IV gastric cancer (GC) patients has been paid much attention recently and it can be defined as surgical treatment aiming at R0 resection after successful chemotherapy, originally unresectable or marginally resectable tumors, technically and/or oncologically. Although the prognosis of stage IV GC has been improving recently with new chemotherapeutic and molecular targeting agents, it is not still satisfactory. With the development and improved response of the chemotherapy regimens, much approaches on conversion therapy for stage IV GC has been successfully demonstrated. However, there is no evidence regarding the benefit of conversion therapy in Stage IV GC. To clarify the meaning of surgical intervention for advanced GC, we retrospectively analyzed 63 Stage IV GC patients treated with S-1/CDDP or S1/TXT. Median survival time (MST) of all patients was 16.5 months and there was no significant difference of MST between the group of S-1/CDDP and S-1/TXT. Twenty-seven patients underwent gastrectomy and severe perioperative complications were not observed. Among the patients that showed response to chemotherapy, MST was extended in the patients who underwent gastrectomy. It is suggested that S-1 based chemotherapy combined with conversion therapy (adjuvant surgery) for Stage IV GC showed acceptable results and it performed safely. We also examined the efficacy of chemotherapy after conversion therapy in Stage IV GC patients. MST of all Stage IV patients with conversion therapy was 31.2 months and MST after conversion therapy was 12.5 months. There was no difference in MST between those who had S1 monotherapy and doublet (combination) therapy. Thirty-six out of 49 patients had relapse and 31 had 2nd line chemotherapy after conversion. RFS of the patients with 2nd line chemotherapy was longer than that of those with only 1st line chemotherapy. In conclusion, further study is needed to confirm the survival benefit of adjuvant surgery. We are now performing the phase II cohort study of gastrectomy after S-1 based chemotherapy for Stage IV GC patients. Furthermore, large scale retrospective and prospective cohort study are being conducted now in Asian countries based on FACO (Federation of Asian Clinical Oncology) consisted of Japanese Society of Clinical Oncology ( JSCO), Korean Association of Clinical Oncology (KACO) and Chinese Society of Clinical Oncology (CSCO), supported by Japanese Gastric Cancer Association (JGCA), Korean Gastric Cancer Association (KGCA) and Gastric Cancer Association of Chinese Anti-cancer Association.