WBC Count and the Risk of Cancer Mortality in a National Sample of U.S. Adults: Results from the Second National Health and Nutrition Examination Survey Mortality Study
- 1Department of Medicine, the Johns Hopkins University School of Medicine, Baltimore, Maryland;
- 2Department of Epidemiology, the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
- 3Tulane University School of Public Health, New Orleans, Louisiana
- Requests for reprints:
Thomas P. Erlinger, Johns Hopkins Medical Institutions, The Welch Center for Prevention, Epidemiology and Clinical Research, 2024 E. Monument Avenue, Suite 2-602, Baltimore, MD 21201. Phone: (410) 614-6466; Fax: (410) 955-0476. E-mail: terlinge@jhmi.edu
Abstract
Inflammation has been shown to be a risk factor for several chronic diseases. Few epidemiologic studies have examined the relationship between markers of inflammation and cancer. The current study included 7,674 Second National Health and Nutrition Examination Survey (NHANES II) participants, 30 to 74 years of age, between 1976 and 1980. Mortality follow-up through December 31, 1992 was assessed using the National Death Index and Social Security Administration Death Master File. A graded association between higher WBC and higher risk of total cancer mortality was observed [highest versus lowest quartile (relative risk [RR] 2.23; 95% confidence interval [CI], 1.53-3.23)] after adjusting for age, sex, and race. After further adjustment for smoking, physical activity, body mass index, alcohol intake, education, hematocrit, and diabetes, WBC remained significantly associated (P trend = 0.03) with total cancer mortality [highest versus lowest quartile (RR 1.66; 95% CI, 1.08-2.56)]. In stratified analyses, increased WBC was associated with higher risk of non-lung cancer (P trend = 0.04), but not lung cancer (P trend = 0.18). Among never smokers, a 1 SD increase in WBC (2.2 × 109 cells/L) was associated with greater risk of total (RR 1.32; 95% CI, 1.05-1.67) and non-lung (RR 1.30; 95% CI, 1.03-1.63) cancer mortality. These findings support the hypothesis that inflammation is an independent risk factor for cancer mortality. Additional studies are needed to determine whether circulating levels of inflammatory markers are associated with increased risk of incident cancer.
Footnotes
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- Accepted February 10, 2004.
- Received March 10, 2003.
- Revision received January 26, 2004.
