The preventive effects of low-dose enteric-coated aspirin tablets on the development of colorectal tumours in Asian patients: a randomised trial.
OBJECTIVE
To evaluate the influence of low-dose, enteric-coated aspirin tablets (100 mg/day for 2 years) on colorectal tumour recurrence in Asian patients with single/multiple colorectal tumours excised by endoscopy.


METHODS
A double-blinded, randomised, placebo-controlled multicentre clinical trial was conducted.


METHODS
311 subjects with single/multiple colorectal adenomas and adenocarcinomas excised by endoscopy were enrolled in the study (152 patients in the aspirin group and 159 patients in the placebo group). Enrolment began at the hospitals (n=19) in 2007 and was completed in 2009.


RESULTS
The subjects treated with aspirin displayed reduced colorectal tumourigenesis and primary endpoints with an adjusted OR of 0.60 (95% CI 0.36 to 0.98) compared with the subjects in the placebo group. Subgroup analysis revealed that subjects who were non-smokers, defined as those who had smoked in the past or who had never smoked, had a marked reduction in the number of recurrent tumours in the aspirin-treated group. The adjusted OR for aspirin treatment in non-smokers was 0.37 (CI 0.21 to 0.68, p<0.05). Interestingly, the use of aspirin in smokers resulted in an increased risk, with an OR of 3.44. In addition, no severe adverse effects were observed in either group.


CONCLUSIONS
Low-dose, enteric-coated aspirin tablets reduced colorectal tumour recurrence in an Asian population. The results are consistent with those obtained from other randomised controlled trials in Western countries. THE CLINICAL TRIAL REGISTRY WEBSITE AND THE CLINICAL TRIAL NUMBER: http://www.umin.ac.jp (number UMIN000000697).
Department of Molecular-Targeting Cancer Prevention, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Hideki
H
Ishikawa
Division of Cancer Prevention Research, National Cancer Center Research Institute, Tokyo, Japan.
Michihiro
M
Mutoh
Department of Public Health, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan.
Sadao
S
Suzuki
Department of Public Health, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan National Institute of Health and Nutrition, Tokyo, Japan.
Shinkan
S
Tokudome
Toho University Ohashi Medical Center, Tokyo, Japan.
Yoshihisa
Y
Saida
Department of Gastroenterology, Takarazuka Municipal Hospital, Hyogo, Japan.
Takashi
T
Abe
Department of Internal Medicine, Toyohashi Municipal Hospital, Aichi, Japan.
Shozo
S
Okamura
Department of Endoscopy, Aichi Cancer Center Hospital, Aichi, Japan.
Masahiro
M
Tajika
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan.
Takashi
T
Joh
Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
Shinji
S
Tanaka
Digestive Disease Center Northern Yokohama Hospital Showa University, School of Medicine, Kanagawa, Japan.
Shin-Ei
SE
Kudo
Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
Takahisa
T
Matsuda
Higashisumiyoshi Morimoto Hospital, Osaka, Japan Department of Lower Gastroenterology, Hyogo College of Medicine, Hyogo, Japan.
Masaki
M
Iimuro
Higashisumiyoshi Morimoto Hospital, Osaka, Japan.
Tomomi
T
Yukawa
Department of Gastroenterology and Oncology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
Tetsuji
T
Takayama
4th Department of Internal Medicine, Sapporo Medical University, School of Medicine, Hokkaido, Japan.
Yasushi
Y
Sato
Moriguchi Keijinkai Hospital, Osaka, Japan.
Kyowon
K
Lee
Department of Gastroenterology, Sakai City Hospital, Osaka, Japan.
Shinji
S
Kitamura
Department of Internal Medicine, Hiroshima City Hospital, Hiroshima, Japan.
Motowo
M
Mizuno
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital East, Chiba, Japan.
Yasushi
Y
Sano
Kimura Hospital, Hyogo, Japan.
Nobuhisa
N
Gondo
Sugimoto Kenji Clinic, Osaka, Japan.
Kenji
K
Sugimoto
Department of Gastrointestinal and Pediatric Surgery Division of Reparative Medicine, Institute of Life Sciences, Mie University Graduate School of Medicine, Mie, Japan.
Masato
M
Kusunoki
Department of Health and Nutrition, Nagoya-Bunri University, Aichi, Japan.
Chiho
C
Goto
Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka, Japan.
Nariaki
N
Matsuura
Department of Molecular-Targeting Cancer Prevention, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Toshiyuki
T
Sakai
Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
Keiji
K
Wakabayashi
D000230:Adenocarcinoma / Q000517:prevention & control*; D000236:Adenoma / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001241:Aspirin / Q000008:administration & dosage / Q000627:therapeutic use*; D003110:Colonic Neoplasms / Q000517:prevention & control*; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D012004:Rectal Neoplasms / Q000517:prevention & control*; D012907:Smoking / Q000453:epidemiology; D013608:Tablets, Enteric-Coated
D016588:Anticarcinogenic Agents; D016861:Cyclooxygenase Inhibitors; D013608:Tablets, Enteric-Coated; D001241:Aspirin
Alcohol; Aspirin; Chemoprevention; Colonic Polyps