Alcohol consumption and colorectal cancer risk: findings from the JACC Study.
BACKGROUND
Because alcohol drinking is a potential risk factor for colorectal cancer, the trend in alcohol consumption in Japan may partly explain the increase in incidence and mortality rates of this malignancy until 1990-1995.


METHODS
We analyzed data from the Japan Collaborative Cohort Study. From 1988 to 1990, 23,708 men and 34,028 women, aged 40-79 years, completed a questionnaire on lifestyle factors including drinking habits. Incidence rate ratios (IRR) were estimated by using proportional hazards models.


RESULTS
During the mean follow-up of 7.6 years through December 1997, we documented 418 incidents of colon cancer and 211 of rectal cancer. Male ex- or current drinkers demonstrated a twofold risk for colon cancer compared with nondrinkers: the multivariate-adjusted IRR was 2.01 (95% confidence interval [CI] 1.09-3.68) for ex-drinkers and 1.97 (95% CI: 1.28-3.03) for current drinkers. The doseresponse relationship between alcohol consumption and the risk, however, was not clear. Female exdrinkers were at an increased risk without statistical significance. For rectal cancer, we found a slightly lower risk in light current drinkers who consumed less than 22 g ethanol per day: the multivariate IRR was 0.61 (95% CI: 0.33-1.13) for men and 0.69 (95% CI: 0.27-1.74) for women. Although the IRR for all current drinkers was almost unity in men, an increasing trend in risk was detected with increasing alcohol consumption in current drinkers (trend p=0.027).


CONCLUSIONS
Taking the findings from our study and other prospective investigations into consideration, more attention should be paid to alcohol consumption in the prevention of colon cancer in Japan.
Wakai
Kenji
K
Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Nagoya, Japan. wakai@aichi-cc.jp
Kojima
Masayo
M
Tamakoshi
Koji
K
Watanabe
Yoshiyuki
Y
Hayakawa
Norihiko
N
Suzuki
Koji
K
Hashimoto
Shuji
S
Kawado
Miyuki
M
Tokudome
Shinkan
S
Suzuki
Sadao
S
Ozasa
Kotaro
K
Toyoshima
Hideaki
H
Ito
Yoshinori
Y
Tamakoshi
Akiko
A
D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires