Associations between circulating eosinophils and cancer risk in the UK Biobank

Eosinophils exhibit anti-tumor cytotoxic responses in the tumor microenvironment and may contribute to tumor immunosurveillance. Analysis of 443,542 adults aged 38-73 years in the UK Biobank, who were initially cancer-free and were followed for a median of 5.8 years, found an inverse association, which met Bonferroni significance, between absolute eosinophil count (AEC) and overall cancer risk (aHR 0.97; 95% CI 0.95-0.98). Notably, 16 cancer types showed borderline associations (p<0.05) with AEC, with 12 types displaying an inverse relationship. These included four hematologic cancers (aHR range 0.58-0.87) and eight nonhematologic cancers (aHR range 0.65-0.95). The authors conclude that the inverse association between AEC and cancer risk suggests a protective role for eosinophils in tumor surveillance.