This article is more than 5 years old. Information may no longer be current.
Hay fever, asthma slightly reduced risk for death from colorectal cancer
Click Here to Manage Email Alerts
People with hay fever and asthma are at a modestly reduced risk for colorectal cancer-related mortality compared with those with neither condition, according to recent results.
Researchers evaluated data from 1,023,191 patients enrolled in the Cancer Prevention Study I (CPS-I) between 1959 and 1972, and 1,102,092 patients in CPS-II between 1982 and 2008. Also assessed were 174,917 patients in the CPS-II Nutrition Cohort subgroup, which was conducted from 1992 to 2007. All participants were aged 30 years and older upon enrollment, and the presence of hay fever and/or asthma was self-reported at baseline.
Hay fever and asthma were present in 2.4% of the CPS-I cohort, 2.2% of the CPS-II cohort and 2.5% of the Nutrition Cohort. Death due to colorectal cancer occurred in 5,644 CPS-I participants, 13,558 CPS-II participants and 3,365 patients in the Nutrition Cohort during follow-up.
Patients with hay fever and asthma were at nonsignificantly reduced risk for death from colorectal cancer in CPS-I (RR=0.90; 95% CI, 0.74-1.09), and at significantly reduced risk in CPS-II (RR=0.79; 95% CI, 0.69-0.91). Meta-analysis of the two cohorts resulted in a statistically significant combined RR of 0.83 (95% CI, 0.74-0.92). A nonsignificant risk reduction in colorectal cancer incidence was observed in the Nutrition Cohort (RR=0.90; 95% CI, 0.71-1.14). No association was observed between hay fever and asthma and colorectal cancer mortality in the Nutrition Cohort (RR=0.99; 95% CI, 0.69-1.44). Sensitivity analysis excluding 950 participants from the CPS-II cohort who also were included in the Nutrition Cohort yielded similar results (RR=0.78; 95% CI, 0.67-0.90).
“Results … indicate that having both asthma and hay fever, a potential marker of atopy, is associated with modestly lower colorectal cancer mortality,” the researchers concluded. “Whether having both hay fever and asthma is associated with colorectal cancer incidence remains unclear. Future research examining associations between colorectal cancer and other potential markers of atopy, such as IgE levels or eosinophil count in prospectively collected blood samples, could clarify the potential importance of IgE-mediated immune reactions in inhibiting colorectal carcinogenesis.”
Click Here to Manage Email Alerts