History of Allergy and Reduced Incidence of Colorectal Cancer, Iowa Women's Health Study

A. E. Prizment, A. R. Folsom, J. R. Cerhan, A. Flood, J. A. Ross, K. E. Anderson
2007 Cancer Epidemiology, Biomarkers and Prevention  
Previous epidemiologic studies have reported that a history of allergy is associated with reduced risk of colorectal cancer and other malignancies. We studied the association between allergy history and incident colorectal cancer (n = 410) prospectively in 21,292 Iowa women followed for 8 years. Allergy was defined from four self-reported questions about physiciandiagnosed asthma (a), hay fever (b), eczema or allergy of the skin (c), and other allergic conditions (d). A history of any allergy
more » ... s inversely associated with incident colorectal cancer: after multivariate adjustment, the hazard ratio (HR) was 0.74 [95% confidence interval (95% CI), 0.59-0.94]. Compared with women with no allergy, women reporting only one of the four types of allergy and women reporting two or more types had HRs of 0.75 (95% CI, 0.56-1.01) and 0.58 (95% CI, 0.37-0.90), respectively (P trend = 0.02). The inverse association persisted in analyses restricted to any type of nonasthmatic allergy (HR, 0.73; 95% CI, 0.56-0.95). HRs were similar for rectal and colon cancers as well as for colon subsites: proximal and distal (HRs for any allergy ranged from 0.63 to 0.78 across these end points). Allergy history, which may reflect enhanced immunosurveillance, is associated with a reduced risk of colorectal cancer. (Cancer Epidemiol Biomarkers Prev
doi:10.1158/1055-9965.epi-07-0468 pmid:18006924 fatcat:a4xx2gmtuvbb3l2u772rg3ycle