Association Between Cigarette Smoking and Colorectal Cancer in the Women’s Health Initiative

• Published in: JNCI : Journal of the National Cancer Institute Vol. 99; no. 22; pp. 1729 - 1735
• Main Authors: Paskett, Electra D., Reeves, Katherine W., Rohan, Thomas E., Allison, Matthew A., Williams, Carla D., Messina, Catherine R., Whitlock, Evelyn, Sato, Alicia, Hunt, Julie R.
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 21-11-2007; Oxford Publishing Limited (England)
• Subjects: Age Factors; Aged; Biological and medical sciences; Colonic Neoplasms - epidemiology; Colonic Neoplasms - etiology; Colorectal cancer; Colorectal Neoplasms - epidemiology; Colorectal Neoplasms - ethnology; Colorectal Neoplasms - etiology; Colorectal Neoplasms - pathology; Confounding Factors (Epidemiology); Ethnic Groups - statistics & numerical data; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Medical sciences; Middle Aged; Multivariate Analysis; Neoplasm Invasiveness; Proportional Hazards Models; Rectal Neoplasms - epidemiology; Rectal Neoplasms - etiology; Risk Assessment; Risk Factors; Smoking; Smoking - adverse effects; Smoking - epidemiology; Smoking Cessation; Smoking Prevention; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Time Factors; Tobacco Smoke Pollution - adverse effects; Tumors; United States - epidemiology; Women's Health; Womens health; United States; North America; America; Human; Rectal disease; Colorectal cancer; Tobacco smoking; Malignant tumor; Epidemiology; Colonic disease; Cigarette; Cancerology; Risk factor; Digestive diseases; Intestinal disease; Adult; Female; Public health; Cancer
• ISSN: 0027-8874; 1460-2105
• DOI: 10.1093/jnci/djm176

The evidence linking cigarette smoking to the risk of colorectal cancer is inconsistent. We investigated the associations between active and passive smoking and colorectal cancer among 146877 Women's Health Initiative participants. Women reported detailed smoking histories at enrollment. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for the association between smoking and overall and site-specific risk of colorectal cancer. Invasive colorectal cancer was diagnosed in 1242 women over an average of 7.8 years (range = 0.003–11.2 years) of follow-up. In adjusted analyses, statistically significant positive associations were observed between most measures of cigarette smoking and risk of invasive colorectal cancer. Site-specific analyses indicated that current smokers had a statistically significantly increased risk of rectal cancer (HR = 1.95, 95% CI = 1.10 to 3.47) but not colon cancer (HR = 1.03, 95% CI = 0.77 to 1.38), compared with never smokers. Passive smoke exposure was not associated with colorectal cancer in adjusted analyses. Thus, active exposure to cigarette smoking appears to be a risk factor for rectal cancer.