Clinical Significance of Gender and Body Mass Index in Asian Patients with Colorectal Cancer.

Objective: Colorectal cancer is a disease closely associated with anthropometric values. This study aimed to evaluate the clinical relevance of gender and body mass index (BMI) with colorectal cancer using a Korean nationwide cohort. Methods: Data of colorectal cancer cohorts between 2012 and 2013 were acquired from the Health Insurance Review and Assessment Service. All patients underwent surgery due to colorectal cancers. Stage IV patients were excluded due to possible clinical heterogeneity. BMI was classified with the World Health Organization criteria. Results: A total of 31,756 patients were analyzed. The underweight group had 33% higher risk of stage III disease (p<0.001). The overweight and obese groups had 20% and 19% lower risk of stage III (p<0.001 and p=0.002, respectively). The underweight and obese groups had higher risk of longest hospitalization period quartile (≥19 days), with odds ratio of 2.26 (p<0.001) and 1.33 (p<0.001), respectively. The overweight group had a 22% lower risk of the longest hospitalization period quartile (p=0.002). Females had 12% lower risk of distal cancer than males (p<0.001). There was no significant relationship between cancer stage and gender. The proportions of patients who were <50 years and ≥70 years old were higher in the females, and the proportions of patients in their 50s and 60s were higher in the males. Conclusions: Cancer stages and hospitalization period varied depending on BMI. Disease location and the age distribution were affected by gender.