Role of body mass index in colon cancer patients in Taiwan

AIM: To determine the effect of body mass index (BMI) on the characteristics and overall outcome of colon cancer in Taiwan. METHODS: From January 1995 to July 2003, 2138 patients with colon cancer were enrolled in this study. BMI categories (in kg/m2) were established according to the classification of the Department of Health of Taiwan. Postoperative morbidities and mortality, and survival analysis including overall survival (OS), diseasefree survival (DFS), and cancer-specific survival (CSS) were compared across the BMI categories. RESULTS: There were 164 (7.7%) underweight (BMI < 18.5 kg/m2), 1109 (51.9%) normal-weight (BMI = 18.5-23.9 kg/m2), 550 (25.7%) overweight (BMI = 24.0-26.9 kg/m2), and 315 (14.7%) obese (BMI ≥ 27 kg/m2) patients. Being female, apparently anemic, hypoalbuminemic, and having body weight loss was more likely among underweight patients than among the other patients (P < 0.001). Underweight patients had higher mortality rate (P = 0.007) and lower OS (P < 0.001) and DFS (P = 0.002) than the other patients. OS and DFS did not differ significantly between normal-weight, overweight, and obese patients, while CSS did not differ significantly with the BMI category. CONCLUSION: In Taiwan, BMI does not significantly affect colon-CSS. Underweight patients had a higher rate of surgical mortality and a worse OS and DFS than the other patients. Obesity does not predict a worse survival.