| Title | Smoking and colorectal cancer in a non-Western population: a prospective cohort study in Japan. | | Author(s) | Wakai K, Hayakawa N, Kojima M, Tamakoshi K, Watanabe Y, Suzuki K, Hashimoto S, Tokudome S, Toyoshima H, Ito Y, Tamakoshi A, JACC Study Group | | Institution | Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Nagoya 464-8681, Japan. | | Source | J Epidemiol 2003 Nov; 13(6):323-32. | | MeSH | Adult
Age Distribution
Aged
Asian Continental Ancestry Group
Cohort Studies
Colorectal Neoplasms
Comorbidity
Confidence Intervals
Female
Humans
Japan
Male
Middle Aged
Multivariate Analysis
Prospective Studies
Questionnaires
Research Support, Non-U.S. Gov't
Risk Assessment
Risk Factors
Sex Distribution
Smoking
| | Abstract | 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 [CI]: 0.72-1.59) for ex-smokers and 1.23 (95% CI: 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% CI: 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. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 14674660 |
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