Prognostic significance of unintentional body weight loss in colon cancer patients

The aim of the present study was to investigate whether unintentional body weight loss (BWL) provides additional clinical information in terms of tumor progression and prognosis in non-metastatic colon cancer. In the present study, a total of 2,406 consecutive colon cancer patients without metastasis were retrospectively enrolled. Unintentional BWL was defined as loss of >5% of body weight within the last 6–12 months, or defined subjectively upon fulfillment of at least two of the following: Evidence of change in clothing size and corroboration of the reported weight loss by family or friend. This category was recorded as present (‘with’) or absent (‘without’). Logistic regression analysis was performed to determine the correlation between BWL and the tumor characteristics and post-operative outcomes of patients with colon cancer. The Cox regression model was used to determine the association of BWL with long-term survival of colon cancer patients. A significant association between BWL and tumor location [right vs. left: Odds ratio (OR)=1.62; P<0.001], tumor size (≥5 vs. <5 cm: OR=2.17; P<0.001), and tumor stage based on the tumor-nodes-metastasis system (T3-T4 vs. T1-T2: OR=2.02; P<0.001). Post-operative morbidity and mortality were not significantly influenced by BWL. Multivariate analysis revealed that BWL was significantly associated with overall survival [with vs. without BWL: Hazard ratio (HR)=1.178; P=0.036] and relapse-free survival (with vs. without BWL: HR=1.332; P=0.003). In conclusion, BWL in patients with colon cancer is not just a symptom, but it is also correlated with tumor location, size and depth, and is a prognostic factor for poor outcomes including overall survival and tumor relapse.