Cancer-Related Malnutrition and Oxidative Stress in Colorectal Cancer Surgery: A Narrative Review of Pathophysiology and Postoperative Outcomes.

Colorectal cancer (CRC) is a major global health concern with high morbidity and mortality, particularly complicated by postoperative complications. This narrative review explores the interplay between cancer-related malnutrition (CRM) and oxidative stress (OS) as key modifiable risk factors influencing surgical outcomes in CRC patients. Drawing on the recent literature, the article analyzes the multifactorial pathophysiology of CRM, including systemic inflammation, micronutrient deficiency, and metabolic derangements, and its role in weakening antioxidant defenses. Concurrently, oxidative stress, marked by elevated reactive oxygen species and impaired redox homeostasis, is linked to impaired wound healing, infection susceptibility, and anastomotic complications. The review highlights that CRM and OS are interdependent, synergistically exacerbating postoperative morbidity. It also emphasizes the diagnostic and therapeutic implications of integrating nutritional screening tools with oxidative biomarkers to optimize perioperative care. Current evidence suggests that early immunonutrition- and redox-modulating strategies may improve surgical resilience, though standardization of biomarkers and intervention protocols remains a challenge. This article underscores the need for individualized, integrated approaches to perioperative management and proposes CRM-OS interaction as a potential predictive model for surgical risk in CRC. The findings advocate for future clinical trials targeting both nutrition and oxidative status to enhance recovery and long-term prognosis.