The Effect of Body Mass Index on Location of Recurrence and Survival in Early-stage Colorectal Cancer

Introduction: Obesity has become one of the major public health problems in many countries. Controversial results were reported in publications on the relationship between obesity and mortality in patients diagnosed with colorectal cancer (CRC) and that receive curative treatment. In this study, we evaluated the effects of body mass index (BMI) on the location of recurrence and disease-free survival (DFS) in patients with early-stage CRC.

Materials And Methods: Patients that were followed up and treated in the Department of Medical Oncology between 1999 and 2016 were retrospectively included in the study. Patients with operated Stage I, II, and III CRC were included in the study. Patients were divided into three groups based on their BMI (kg/m) of below 25, between 25 and 30, and above 30.

Results: A total of 950 patients, of which 527 (55.5%) were male and 423 (44.5%) were female, were included in the study. The median age of the patients was 56 years. Of the patients, 408 (42.4%) had BMI of <25, 370 (38.9%) had BMI between 25 and 30, and 172 (18.2%) had BMI of ≥30. Local recurrence rate was significantly higher in the group with BMI ≥30 compared to the other groups (P <0.01). When compared with DFS, there was a statistically significant difference between groups with BMI of <25 and ≥30 (P = 0.02) and that difference was more evidently observed in Stage III (P = 0.02). There was no statistically significant difference of overall survival in the BMI groups (P = 0.87). In multivariate analysis, the BMI ≥30 (hazard ratio [HR], 1.49, 95% confidence interval [CI], 1.02-2.17), rectal tumor (HR, 1.70, 95% CI, 1.15-2.51), Stage III (HR, 3.91, 95% CI, 1.86-8.25), number of positive lymph nodes (HR, 1.05, 95% CI, 1.03-1.07), and R1 resection (HR, 3.47, 95% CI, 1.71-7.05) were identified as independent risk factors negatively affecting DFS.

Conclusion: In this study, we observed that the high BMI increased the risk of recurrence, especially in Stage III CRC patients, and that the recurrence frequently occurred locally.