Does body mass index impact the number of LNs harvested and influence long-term survival rate in patients with stage III colon cancer?

Background The aim of this study is to evaluate whether different body mass index (BMI) values affect lymph node (LN) retrieval and whether such variations influence long-term survival in Asian patients. Method From January 1995 to July 2003, 645 stage III colon cancer patients were enrolled in our study. Patients were stratified into four groups: Obese (BMI a parts per thousand 27 kg/m(2)), overweight (24 a parts per thousand currency sign BMI < 27 kg/m(2)), normal (18.5 a parts per thousand currency sign BMI < 24 kg/m(2)), and underweight (BMI < 18.5 kg/m(2)). Results Mean BMI in the cohort was 23.3 kg/m(2). Mean number of LNs harvested was 23.1, 19.5, 19.8 and 28.1 in the normal, overweight, obese and underweight groups, respectively. There was a significant difference in the mean number of LNs harvested when comparing the overweight and underweight groups to the normal group (p = 0.013 and p = 0.04, respectively). Females were overrepresented in the underweight group (p = 0.011), and patients who had proximal colon cancers were more frequently underweight (p = 0.018). The mean number of LNs harvested varied by cases of right hemicolectomy (p = 0.009) and proximal cancer location (p = 0.009) for different BMI groups. Multivariate analysis showed that underweight, proximal colon cancer, well- or moderately differentiated adenocarcinoma and stage IIIC cancer were significant variables for adequate LN recovery. BMI was not significantly associated with relapse-free survival (p = 0.523) or overall survival (p = 0.127). Conclusion BMI is associated with LN harvest but is not an independent variable in stage III colon cancer survival.