Effect of body mass index on the outcome of patients with rectal cancer receiving curative anterior resection: disparity between the upper and lower rectum.
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.
You
Jeng-Fu
JF
Colorectal Section, Department of Surgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Linko, Taiwan. you3368@adm.cgmh
Tang
Reiping
R
Changchien
Chung Rong
CR
Chen
Jinn-Shiun
JS
You
Yau-Tong
YT
Chiang
Jy-Ming
JM
Yeh
Chien-Yuh
CY
Hsieh
Pao-Shiu
PS
Tsai
Wen-Sy
WS
Fan
Chung-Wei
CW
Hung
Hsin-Yuan
HY
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