Cigarette smoking and colorectal carcinoma mortality in a cohort with long-term follow-up.
BACKGROUND
Evidence suggests that colorectal carcinoma (CRC) may be a tobacco-associated malignancy.


METHODS
In the current study, the authors examined the association between cigarette smoking and CRC mortality in the Chicago Heart Association Detection Project in Industry study, a cohort of 39,299 men and women with an average of 26 years of follow-up. To assess whether the association was stronger in participants with a potentially long history of smoking, the authors also stratified the analysis using a baseline age > or = 50 years versus < 50 years.


RESULTS
Using multivariate Cox regression analysis, there was a marginally significant trend (P = 0.06) for men and women combined between smoking and CRC mortality. In the age-stratified analysis in the older participant group, there was no apparent association for men, women, or men and women combined. In the younger participant group, there appeared to be dose-response relations for women and for men and women combined (P value for trend = 0.008 and 0.03, respectively) between smoking and CRC mortality. The relative risk for women who smoked >20 cigarettes/day compared with never smokers was 2.49 (95% confidence interval [95% CI], 0.87-7.12), and was 1.87 for men and women combined (95% CI, 1.08-3.22).


CONCLUSIONS
The results of the current study support an association between cigarette smoking and CRC mortality, particularly in women age < 50 years.
Colangelo
Laura A
LA
Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, 680 North Lake Shore Drive, Suite 1102, Chicago, IL 60611, USA.
Gapstur
Susan M
SM
Gann
Peter H
PH
Dyer
Alan R
AR
D000328:Adult; D000367:Age Factors; D000368:Aged; D002277:Carcinoma / Q000209:etiology / Q000401:mortality*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000209:etiology / Q000401:mortality*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*