Increased Risk of a Cancer Diagnosis after Herpes Zoster Ophthalmicus: A Nationwide Population-Based Study

Abstract

Herpes zoster has been associated with immune suppression, as has an increased risk of cancer. This population-based follow-up study aimed to investigate the risk of a subsequent cancer diagnosis after herpes zoster ophthalmicus (HZO). A retrospective cohort study. Retrospective claims data from the Taiwan National Health Insurance Research Database were analyzed. The study cohort comprised all patients with a diagnosis of HZO (International Classification of Diseases, 9th Revision, Clinical Modification code 053.2) in 2003 and 2004 (n=658). The comparison cohort consisted of randomly selected ambulatory care patients, 8 for every patient with HZO (n=5264) matched with the study group on age, gender, monthly income, and urbanization level of the patient's residence. The Kaplan-Meier method was used to compute 1-year cancer-free survival rate. Stratified Cox proportional hazard regressions were carried out to compute the adjusted 1-year cancer-free survival rate after adjusting for potential confounding factors. Subsequent claims for all study and comparison patients were captured over a 1-year follow-up period from their index ambulatory care visit to identify whether the patient received a cancer diagnosis during the follow-up period. During 1-year follow-up, cancer was diagnosed in 4.86% of patients with HZO and 0.53% of patients in the comparison cohort. Patients with HZO had significantly lower 1-year cancer-free survival rates than the comparison cohort. After adjusting for patient age, gender, monthly income, and urbanization level, patients with HZO were found to have a 9.25-fold (95% confidence interval, 5.51-15.55) risk of a subsequent cancer diagnosis than the matched comparison cohort. No significant differences in cancer type were observed between the 2 cohorts. Herpes zoster ophthalmicus may be a marker of increased risk of being diagnosed with cancer in the following year. The author(s) have no proprietary or commercial interest in any materials discussed in this article.