TY - JOUR
T1 - Smoking and colorectal cancer in a non-western population
T2 - A prospective cohort study in Japan
AU - Wakai, Kenji
AU - Hayakawa, Norihiko
AU - Kojima, Masayo
AU - Tamakoshi, Koji
AU - Watanabe, Yoshiyuki
AU - Suzuki, Koji
AU - Hashimoto, Shuji
AU - Tokudome, Shinkan
AU - Toyoshima, Hideaki
AU - Ito, Yoshinori
AU - Tamakoshi, Akiko
PY - 2003/11
Y1 - 2003/11
N2 - BACKGROUND: The risk of colorectal cancer in relation to smoking habits has been examined mostly in Caucasians, and evidence for other ethnic groups is still scarce. METHODS: Our data came from the Japan Collaborative Cohort (JACC) Study. From 1988 through 1990, 25,260 men and 34,619 women aged 40-79 years completed a questionnaire on cigarette smoking and other lifestyle factors. Hazard ratios (HR) were estimated by fitting proportional hazards models. RESULTS: During the mean follow-up of 7.6 years through December 1997, we documented 408 incident colon cancers and 204 rectal cancers. We found a non-significant increase in colon cancer risk in male current smokers compared with never smokers. The multivariate-adjusted hazard ratios were 1.07 (95% confidence interval [Cl]: 0.72-1.59) for ex-smokers and 1.23 (95% Cl: 0.85-1.78) for current smokers. We however failed to observe a clear dose-response relationship between smoking intensity or duration and colon cancer risk. The adjusted hazard ratio was 1.07 (95% Cl: 0.71-1.61) even for 40+ years of smoking. Almost no increase in colon cancer risk was detected for female smokers, and male smokers were not at an enhanced risk of rectal cancer. CONCLUSIONS: Cigarette smoking was not a strong risk factor for colorectal cancer even after a long-term exposure, although a weak association remains open to discussion.
AB - BACKGROUND: The risk of colorectal cancer in relation to smoking habits has been examined mostly in Caucasians, and evidence for other ethnic groups is still scarce. METHODS: Our data came from the Japan Collaborative Cohort (JACC) Study. From 1988 through 1990, 25,260 men and 34,619 women aged 40-79 years completed a questionnaire on cigarette smoking and other lifestyle factors. Hazard ratios (HR) were estimated by fitting proportional hazards models. RESULTS: During the mean follow-up of 7.6 years through December 1997, we documented 408 incident colon cancers and 204 rectal cancers. We found a non-significant increase in colon cancer risk in male current smokers compared with never smokers. The multivariate-adjusted hazard ratios were 1.07 (95% confidence interval [Cl]: 0.72-1.59) for ex-smokers and 1.23 (95% Cl: 0.85-1.78) for current smokers. We however failed to observe a clear dose-response relationship between smoking intensity or duration and colon cancer risk. The adjusted hazard ratio was 1.07 (95% Cl: 0.71-1.61) even for 40+ years of smoking. Almost no increase in colon cancer risk was detected for female smokers, and male smokers were not at an enhanced risk of rectal cancer. CONCLUSIONS: Cigarette smoking was not a strong risk factor for colorectal cancer even after a long-term exposure, although a weak association remains open to discussion.
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U2 - 10.2188/jea.13.323
DO - 10.2188/jea.13.323
M3 - Article
C2 - 14674660
AN - SCOPUS:1542703793
SN - 0917-5040
VL - 13
SP - 323
EP - 331
JO - Journal of epidemiology
JF - Journal of epidemiology
IS - 6
ER -