Supplementary Material for: Pathologic Outcomes and Survival in Patients with Rectal Cancer and Increased Body Mass Index

Introduction: We assessed any association between increased body mass index (BMI) and rectal cancer outcomes.
Methods: We included patients who underwent surgery for stage I-III rectal adenocarcinoma who were divided according to BMI at diagnosis: ideal BMI (18.5-24.9 kg/m2) and increased BMI (≥25 kg/m2). Groups were compared using univariate association analyses relative to baseline characteristics, pathologic outcomes, overall survival (OS) and disease-free survival (DFS). Main outcome measures involved circumferential resection margin (CRM), pathologic TNM stage, total mesorectal incision (TME) grade, OS, and DFS.
Results: 243 patients (64.6% male; median age 59 years) with median BMI of 26.3 kg/m2 were included. 62.1% had BMI ≥25 kg/m2. Increased BMI patients had similar proportions of males (66.9% vs 60.9%;p=0.407) and comorbidities (ASA III: 47% vs 37.4%;p=0.24) to ideal BMI patients. There were no significant differences in cN1-2 stage (p=0.279) or positive CRM (p=0.062) rates. The groups had similar complete/near-complete TME, pathologic TN stage, and survival rates. Pathologic and survival outcomes were also similar with a BMI cutoff of 30.
Conclusions: There was a trend toward more nodal involvement in preoperative assessment and less CRM involvement in the final pathology of increased BMI patients. Complete/near-complete TME and survival rates were comparable between the groups.