Megestrol Acetate in Improving Neoadjuvant Chemotherapy-Related Weight Loss in Locally Advanced CRC

This clinical trial is an open-label, prospective, multicenter, randomized study. The aims of this study are to evaluate the effects of megestrol acetate (MA) on ameliorating neoadjuvant chemotherapy-related weight loss, anorexia, nutritional deterioration, andChemotherapy-related adverse events in patients with locally advanced colorectal cancer (LACRC), while comprehensively assessing its safety profile. Eligible participants will be randomly assigned in a 1:1 ratio to either the experimental group or the control group. Participants in the experimental group will receive 6 cycles of neoadjuvant chemotherapy regimen of mFOLFOX6 (intravenous oxaliplatin 85 mg/m2, leucovorin 400 mg/m2, 5-fluorouracil 400 mg/m2, and 5-fluorouracil 2400 mg/m2 continuous pumping for 48 hours) administered every 14 days, combined with oral MA suspension at a dose of 625 mg/day. MA treatment will be maintained until the completion of neoadjuvant chemotherapy. Participants in the control group will receive 6 cycles of the mFOLFOX6 neoadjuvant chemotherapy regimen without concurrent administration of MA. Subjects in both the experimental and control groups will undergo radical surgical treatment after completing the neoadjuvant therapy. Those achieving pCR based on postoperative pathology will be regularly followed up according to the follow-up protocol. Participants who do not achieve pCR will receive six cycles of adjuvant therapy after surgery, followed by regular follow-up assessments as outlined in the protocol after completing the final cycle of adjuvant therapy. The primary outcome of this study is the incidence of weight loss (defined as \>5% body weight reduction during neoadjuvant therapy). Secondary objectives include: 1) Appetite evaluation; 2) Nutritional parameter dynamics; 3) Quality of life (QoL) assessment with the EORTC QLQ-C30 questionnaire; 4) Incidence of neoadjuvant chemotherapy-related adverse events; 5) Oncological response; 6) Surgical morbidity; 7) Postoperative recovery metrics: time to first flatus/bowel movement, length of postoperative hospitalization, and 30-day readmission rates; 8) Survival outcomes: 1-year disease-free survival (DFS), Overall survival (OS).