Endoscopic Evaluation of Neoadjuvant Chemotherapeutic Efficacy in Gastric Cancer before Gastrectomy Might be as Useful as Histological Assessment after Gastrectomy.

BACKGROUND: Neoadjuvant chemotherapy for advanced gastric cancer is expected to improve prognoses. However, as there is no method to evaluate neoadjuvant chemotherapeutic efficacy before gastrectomy, some patients at high risk for a poor prognosis undergo gastrectomy. The aim of the present study was to investigate whether endoscopy could be useful for assessing the efficacy of neoadjuvant chemotherapy. METHODS: In this retrospective study, we analyzed the data of 41 patients who received neoadjuvant chemotherapy followed by gastrectomy at our institution to investigate whether responsiveness to neoadjuvant chemotherapy, as assessed with endoscopy, can serve as a surrogate marker for histological grades 1b or higher in the Japanese Classification of Gastric Carcinoma (JCGC) scheme. RESULTS: There were 32 (78.0%) responders and 9 (22.0%) nonresponders to neoadjuvant chemotherapy, as observed in endoscopic evaluations. Among the endoscopic responders, 24 (75.0%) had cancer of histological grade 1b or higher, and 15 (46.9%) had cancer of grade 2 or higher. Among the endoscopic nonresponders, 1 (11.1%) patient had histological grade 1b cancer. Compared with endoscopic nonresponders, endoscopic responders were more likely to show a histological response (chi-square test: p = 0.0005 for JCGC grade 1b or higher; p = 0.0099 for JCGC grade 2 or higher). CONCLUSIONS: Most endoscopic responders showed JCGC histological responses. Evaluation of neoadjuvant chemotherapeutic efficacy by endoscopy in gastric cancer may be useful before gastrectomy. As this was a retrospective study, further investigations are required. The protocol was approved by the ethics review committee at Osaka Medical College (No. 2422) and was registered in the University Hospital Medical Information Network Clinical Trial Registry (UMIN000033088).