Active smoking and mortality among colorectal cancer survivors: the Cancer Prevention Study II nutrition cohort

• Published in: Journal of clinical oncology Vol. 33; no. 8; pp. 885 - 893
• Main Authors: Yang, Baiyu, Jacobs, Eric J, Gapstur, Susan M, Stevens, Victoria, Campbell, Peter T
• Format: Journal Article
• Language: English
• Published: United States 10-03-2015
• Subjects: Aged; Aged, 80 and over; Cause of Death; Cohort Studies; Colorectal Neoplasms - complications; Colorectal Neoplasms - mortality; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Multivariate Analysis; Neoplasm Invasiveness; Neoplasm Metastasis; Nutritional Sciences; Proportional Hazards Models; Sensitivity and Specificity; Smoking - adverse effects; Smoking Cessation; Surveys and Questionnaires; Survivors; Tobacco Use Disorder - complications; Treatment Outcome; United States; United States
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2014.58.3831

Active smoking is associated with higher colorectal cancer risk, but its association with survival after colorectal cancer diagnosis is unclear. We investigated associations of smoking, before and after diagnosis, with all-cause and colorectal cancer-specific mortality among colorectal cancer survivors.
From a cohort of adults who were initially free of colorectal cancer, we identified 2,548 persons diagnosed with invasive, nonmetastatic colorectal cancer between baseline (1992 or 1993) and 2009. Vital status and cause of death were determined through 2010. Smoking was self-reported on the baseline questionnaire and updated in 1997 and every 2 years thereafter. Postdiagnosis smoking information was available for 2,256 persons (88.5%).
Among the 2,548 colorectal cancer survivors, 1,074 died during follow-up, including 453 as a result of colorectal cancer. In multivariable-adjusted Cox proportional hazards regression models, prediagnosis current smoking was associated with higher all-cause mortality (relative risk [RR], 2.12; 95% CI, 1.65 to 2.74) and colorectal cancer-specific mortality (RR, 2.14; 95% CI, 1.50 to 3.07), whereas former smoking was associated with higher all-cause mortality (RR, 1.18; 95% CI, 1.02 to 1.36) but not with colorectal cancer-specific mortality (RR, 0.89; 95% CI, 0.72 to 1.10). Postdiagnosis current smoking was associated with higher all-cause (RR, 2.22; 95% CI, 1.58 to 3.13) and colorectal cancer-specific mortality (RR, 1.92; 95% CI, 1.15 to 3.21), whereas former smoking was associated with all-cause mortality (RR, 1.21; 95% CI, 1.03 to 1.42).
This study adds to the existing evidence that cigarette smoking is associated with higher all-cause and colorectal cancer-specific mortality among persons with nonmetastatic colorectal cancer.