title: Increased risk of a cancer diagnosis after herpes zoster ophthalmicus: a nationwide population-based study.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  A retrospective cohort study.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Herpes zoster ophthalmicus may be a marker of increased risk of being diagnosed with cancer in the following year.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Department of Ophthalmology, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Jau-Der
authors.initials: JD
authors.lastname: Ho
authors.forename: Sudha
authors.initials: S
authors.lastname: Xirasagar
authors.forename: Herng-Ching
authors.initials: HC
authors.lastname: Lin
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006563:Herpes Zoster Ophthalmicus / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D011159:Population Surveillance; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology