Purpose: Obesity is considered a risk factor for colon cancer. Worse outcome observed in colon cancer patients with obesity may have several mechanisms. However, the influence of obesity on colon cancer stage is yet to be clarified. The objective of this study was to determine the relationship between obesity and stage on presentation.
Methods: This is a retrospective analysis of patients' files in one university affiliated medical center. Included in this study were non-metastatic patients who underwent colectomy for adenocarcinoma of the colon in whom both the preoperative abdominal computed tomography and the postoperative pathology report were available for evaluation. Abdominal computed tomography measurement of retroperitoneal fat thickness was used as an indicator of obesity. Data was analyzed according to quartiles of fat thickness.
Results: Of 83 patients, 38 were males and 45 were females. Median age was 71 years (range 43-90 years). Increased retroperitoneal fat thickness was not associated with advanced T and N stages on presentation. Rather, patients in the first quartile presented with the worst T and N stages. The proportion of patients with T3 and T4 tumors was 95, 76.2, 66.7, and 66.7% in quartiles 1, 2, 3, and 4, respectively (p = 0.0327), while the proportion of patients with positive lymph node metastasis was 60, 23.8, 23.8, and 42.9% in quartiles 1, 2, 3, and 4, respectively (p = 0.0319).
Conclusions: The data presented here does not support the association of obesity with worse stage at presentation of colon cancer, and other possible mechanisms for worse outcome should be sought.
Keywords: Colon adenocarcinoma; Colon cancer staging; Computed tomography; Retroperitoneal fat thickness; Visceral fat.