Alterations in Body Composition Lead to Changes in Postoperative Outcome and Oncologic Survival in Patients with Non-Metastatic Colon Cancer

<b>Background/Objectives</b>: Opinions concerning the role of obesity and changes in muscle mass in individuals with malignancies vary. It is believed that decreased fat tissue leads to a higher complication rate, while decreased muscle mass results in a poorer oncologic outcome. This study aimed to evaluate the impact of fat distribution and skeletal muscle mass on postoperative morbidity and long-term oncological outcomes in patients with non-metastatic colon cancer. <b>Methods</b>: Between 2012 and 2018, a total of 129 patients with stage I-III colon cancer were evaluated. Abdominal CT scans were used to assess muscle mass and fat tissue (subcutaneous and visceral). Differences in postoperative morbidity and long-term oncologic outcome were analyzed and compared. <b>Results</b>: No significant differences occurred concerning complication rate or anastomotic leakage. Individuals with altered body composition parameters had a shorter length of hospital stay (<i>p</i> = 0.046) and an increased duration of surgery (<i>p</i> = 0.029). In patients with an ASA III score, altered fat tissue distribution was associated with improvements in both overall and disease-free survival (<i>p</i> = 0.031 and <i>p</i> = 0.027, respectively) but also resulted in longer hospital stay. <b>Conclusions</b>: Changes in body composition parameters lead to alterations in economic factors as well as changes in oncologic survival, especially in patients with higher ASA scores. No differences in morbidity were observed.