Obesity was associated with a decreased postoperative recurrence of rectal cancer in a Japanese population.
OBJECTIVE
Obesity contributes to the technical difficulty of rectal surgery and is considered to be a risk factor for postoperative complications. The impact of obesity on the long-term outcomes of rectal cancer surgery remains unclear.


METHODS
A total of 263 consecutive rectal cancer patients who underwent surgery were categorized into two groups according to the body mass index (BMI) based on the Asian BMI classification: non-obese (BMI <25 kg/m(2)) and obese (BMI ≥25 kg/m(2)). The postoperative survival and recurrence rates and oncological surgical quality indicators were compared between groups using the univariate and multivariate analyses. The differences in recurrence patterns were assessed by a competing risk regression analysis.


RESULTS
64 (24%) patients were included in the obese group. The number of retrieved lymph nodes was significantly greater in the non-obese group than in the obese group (22.4 vs. 16.0, P < 0.01). The 5-year disease-free survival (DFS) rates were 86.5 and 68.8% in the obese and non-obese groups, respectively (P = 0.01). The multivariate analysis demonstrated that obesity significantly decreased the postoperative recurrence rate (P = 0.04). Moreover, the BMI was significantly associated with distant metastasis (P = 0.04).


CONCLUSIONS
Obese rectal cancer patients have high DFS rates and a decreased incidence of distant metastases compared to non-obese patients. The BMI may be a key factor for predicting the postoperative prognosis and determination of an appropriate strategy for the treatment of rectal cancer patients.
Department of Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 1608582, Japan.
Ryo
R
Seishima
Koji
K
Okabayashi
Hirotoshi
H
Hasegawa
Daisuke
D
Sugiyama
Yoshiyuki
Y
Ishii
Masashi
M
Tsuruta
Toru
T
Takebayashi
Yuko
Y
Kitagawa
D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009765:Obesity / Q000503:physiopathology; D012004:Rectal Neoplasms / Q000401:mortality* / Q000601:surgery*; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome