Neoadjuvant chemotherapy or adjuvant chemotherapy is similarly beneficial for locally advanced gastric cancer patient

Abstract Background: Different types of neoadjuvant chemotherapy regimens have been compared for gastric cancer, mostly in terms of radiological downgrading or pathological tumor regression, however, there was no large-scale multicenter RCT study that conducted head-to-head comparison for overall survival rate between the perioperative or neoadjuvant chemotherapy(NAC) and postoperative or adjuvant chemotherapy(AC). We explored whether the five years overall survival rate is greater in the patients who had perioperative chemotherapy plus surgery compared to those who underwent surgery first and postoperative chemotherapy. Methods: Altogether 77 patients with the clinical diagnosis of cTNM stage III were included. Five years overall survival rates(OS) were compared between the patients who underwent neoadjuvant chemotherapy plus surgery (NAC) and the patients who had surgery first plus adjuvant chemotherapy (AC). A propensity score matching was applied for adjusting the disparity between the two groups. A Kaplan-Meier plot was created for survival analysis, Log Rank method was used to compare the difference in OS. Results: A total of 34 patients were in the NAC group and 43 patients in the AC group. There was no significant difference in age (median 64 vs 66 years), cTNM staging, and extent of gastrectomy between the two groups (p<0.05). The median follow-up time was 58 months (range of 53-65 months). Five years of overall survival (OS) for the patients in the NAC group and AC group were 61.8% and 73.5% respectively. There was no statistical difference between the two groups in five years' overall survival rates (p>0.05). There was no significant difference in the severity grading of postoperative complications between the two groups (p>0.05). Conclusions: There was no significant difference in five years overall survival rate between the patients who had perioperative chemotherapy plus surgery compared to those who had surgery first plus postoperative chemotherapy. A well-controlled prospective study is necessary to reconfirm whether perioperative chemotherapy is superior to postoperative chemotherapy for gastric cancer patients. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The overall costs of this research will be funded by grants from the National Natural Science Foundation of China No. 81871904 (ZG Zhu), and No.82103396(ZJ Yu). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Ethics Committee of Ruijin Hospital approved this study and waived the individual informed consent due to the retrospective analysis. The study was carried out in conformity with the Declaration of Helsinki (as revised in 2013) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.