Objective: This study aims to evaluate postoperative morbidity and mortality in locally advanced non-metastatic colon cancers treated with neoadjuvant chemotherapy (CT) with FOLFOX-4 versus surgery.
Methods: This is a prospective, mono-centric, comparative and randomized 2-arm study. From November 2016 to November 2019, 71 patients with colon cancer (ctT3M0, ctT4aM0 and ctT4bM0) classified on the abdomino-pelvic scan as locally advanced and non-metastatic were randomized to two treatment regimens. Patients in arm A receive simplified FOLFOX-4-based preoperative chemotherapy for 4 cycles, followed by laparotomy colectomy and then simplified FOLFOX-4-based postoperative chemotherapy for an additional 8 cycles. Patients in arm B benefit from laparotomy colectomy followed by 12 cycles of simplified FOLFOX-4 postoperative chemotherapy. The primary endpoint is the evaluation of postoperative morbidity and mortality defined according to the Clavien and Dindo classification in both arms.
Results: The 2 groups (control n=36; folfox n=35) were comparable for demographic and tumor data. Two patients in the control group did not have resection of the primary tumor (PT): peritoneal carcinosis of intraoperative discovery (n=1), PT deemed unresectable (n=1) .91% had the entire preoperative CT (12.5% toxicity grade ? 3). Only one patient (2.8%) had a CT-associated primary tumor complication. Post-operative mortality (1.45%) and severe morbidity (5.8%) were comparable between the 2 groups (p= 0.99). 100% of patients had an R0 resection. In the control group, no patient was stage I. In the folfox arm, downsizing (48mm vs 59 mm; p=0.001) and tumor downstaging were observed with more stage I (p=0.022) and less stage III (p=0.088), less vascular emboli (p=0.103), lymphatic invasion (p=0.038) and perineural invasion (p=0.49).
Conclusion: Neoadjuvant chemotherapy in locally advanced non-metastatic colon cancer is feasible and tolerable, with no increase in postoperative morbidity and no added risk of complication of the primary tumor under neoadjuvant chemotherapy. It leads to tumor downsizing and dowstaging. 

Professor Amoura Mohand Ouahmed obtained his diploma in specialized medical studies in general surgery, his master's degree in general surgery and his doctorate in medical sciences. He is an associate professor in general surgery at the Faculty of Medicine of the University of Algiers in Algeria. He is a member of the Algerian Society of Surgery.