Efficacy and Safety of FLOT regimen vs DCF, FOLFOX, and ECF regimens as Perioperative Chemotherapy Treatments for Resectable Gastric Cancer PatientsShort title: Comparative Study of Chemotherapy Regimens for Gastric Cancer

Aim: This study aimed to evaluate and compare the efficacy and toxicity of common regimens used as perioperative chemotherapy including ECF, DCF, FOLFOX, and FLOT to identify the most effective chemotherapy regimen with less toxicity. Material and Methods: This retrospective cohort study was based on 152 eligible gastric cancer patients recruited in a tertiary oncology hospital in Isfahan, Iran (2014-2019). All resectable gastric cancer patients who had received one of the four chemotherapy regimens including ECF, DCF, FOLFOX, or FLOT, and followed for at least one year (up to five years) were included. The primary endpoint of this study was Overall Survival (OS), Progression-Free Survival (PFS), Overall Response Rate (ORR), and R0 resection. We also considered toxicity according to CTCAE (v.4.0) criteria as a secondary endpoint. Cox -regression models were used applied to estimate OS and PFS time, controlled for relevant covariates. Results: Of included patients, 32(21%), 51(33.7%), 37(24.3%), and 32(21%) had received ECF, DCF, FOLFOX and FLOT, respectively. After the median 25 months follow-up, overall survival was higher with the FLOT regimen in comparison with other regimens (hazard ratio [HR] = 0. 052). The median OS of the FLOT regimen was not reachable in Kaplan-Meier analysis and the median OS was 28, 26, and 23 months for DCF, FOLOFX, and ECF regimens, respectively. On the other hand, a median PFS of 25, 17, 15, and 14 months was observed for FLOT, DCF, FOLFOX, and ECF regimens, respectively (Log-rank = 0. 021). FLOT regimen showed 84. 4% ORR which was notably higher than other groups (p-value<0. 01). Conclusions: For resectable gastric cancer patients, the perioperative FLOT regimen seemed to lead to a significant improvement in patient OS and PFS in comparison with ECF, DCF, and FOLFOX regimens. As such, the FLOT regimen could be considered as the optimal option for managing resectable gastric cancer patients.