title: Effect of body mass index on the outcome of patients with rectal cancer receiving curative anterior resection: disparity between the upper and lower rectum.
abstract: OBJECTIVE
  The aim of this study was to investigate the effect of body mass index (BMI) on local recurrence of primary rectal cancer after open curative sphincter-saving resection.
  
  
  BACKGROUND
  Increasing BMI was reported to be associated with a higher likelihood of local recurrence in male patients with rectal cancer. However, it remained unclear whether BMI exerts the same effects on local recurrence of rectal cancer in the upper and lower rectum.
  
  
  METHODS
  Between January 1995 and December 2002, we investigated 1873 patients with well-documented body height and body weight who underwent curative anterior resection for primary rectal cancer in a single institution. The patients were assigned to 4 groups according to their BMI: underweight, normal, overweight, and obese.
  
  
  RESULTS
  The frequency of local recurrence increased with an increase in the BMI in patients with lower rectal cancer. The local recurrence rates were 2.5% (2 of 79), 6.1% (48 of 782), 9.2% (39 of 424), and 13.8% (9 of 65) in underweight, normal, overweight, and obese patients with lower rectal cancer, respectively. These results were different from those of patients with upper rectal cancer. Independent risk factors for local recurrence in the lower rectal cancer group were BMI, resection margin, histologic grade of differentiation, depth of tumor invasion, and status of lymph node metastases. In the upper rectal cancer group, the depth of tumor invasion and histologic grade of differentiation reached statistical significance.
  
  
  CONCLUSIONS
  BMI exerted different effects on local recurrence of rectal cancer in the upper and lower rectum. Further, more aggressive adjuvant and/or neoadjuvant treatments should be considered for patients with tumor in the lower rectum and with higher BMI.
authors.affiliation: Colorectal Section, Department of Surgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Linko, Taiwan. you3368@adm.cgmh
authors.forename: Jeng-Fu
authors.initials: JF
authors.lastname: You
authors.forename: Reiping
authors.initials: R
authors.lastname: Tang
authors.forename: Chung Rong
authors.initials: CR
authors.lastname: Changchien
authors.forename: Jinn-Shiun
authors.initials: JS
authors.lastname: Chen
authors.forename: Yau-Tong
authors.initials: YT
authors.lastname: You
authors.forename: Jy-Ming
authors.initials: JM
authors.lastname: Chiang
authors.forename: Chien-Yuh
authors.initials: CY
authors.lastname: Yeh
authors.forename: Pao-Shiu
authors.initials: PS
authors.lastname: Hsieh
authors.forename: Wen-Sy
authors.initials: WS
authors.lastname: Tsai
authors.forename: Chung-Wei
authors.initials: CW
authors.lastname: Fan
authors.forename: Hsin-Yuan
authors.initials: HY
authors.lastname: Hung
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery*; D000368:Aged; D015992:Body Mass Index; D003082:Colectomy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D050177:Overweight; D012004:Rectal Neoplasms / Q000601:surgery*; D012007:Rectum / Q000601:surgery*; D013851:Thinness; D016896:Treatment Outcome