The risk of cancer in patients with generalized anxiety disorder: a nationwide population-based study

PLoS One. 2013;8(2):e57399. doi: 10.1371/journal.pone.0057399. Epub 2013 Feb 27.

Abstract

Objective: To evaluate the risk of cancer among patients with generalized anxiety disorder (GAD) in a nationwide population-based dataset.

Methods: We recruited newly-diagnosed GAD patients aged 20 years or older without antecedent cancer from the Taiwan National Health Insurance Research database between 2000-2010. Standardized incidence ratios (SIRs) of cancers were calculated in GAD patients, and the subgroup of GAD patients diagnosed by psychiatric specialists.

Results: A total of 559 cancers developed among 19,793 GAD patients with a follow-up of 89,485 person-years (median follow-up of 4.34 years), leading to a significantly increased SIR of 1.14 [95% confidence interval (CI) 1.05-1.24]. Male GAD patients had a significantly increased SIR overall (1.30, 95% CI 1.15-1.46) and for lung and prostate cancer (1.77, 95% CI 1.33-2.30 and 2.17, 95% CI 1.56-2.93, respectively). Patients over 80 years of age also had a significantly increased SIR (1.56, 95% CI 1.25-1.92), especially in males. However, psychiatrist-diagnosed GAD patients did not show increased cancer risk relative to the general population, perhaps due to having fewer physical comorbidities than non-psychiatrist-diagnosed GAD patients.

Conclusion: This study found that overall cancer risk is elevated among patients with GAD. The risk of lung and prostate cancer also increased in male patients with GAD. This increased cancer risk may be due to physical comorbidities and surveillance bias. Further prospective study is necessary to confirm these findings.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anxiety Disorders / complications*
  • Demography
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Neoplasms / diagnosis
  • Neoplasms / epidemiology*
  • Neoplasms / etiology*
  • Neoplasms / psychology
  • Risk Factors
  • Taiwan / epidemiology
  • Young Adult

Grants and funding

This study is based in part on data from the National Health Insurance Research Database provided by the Bureau of National Health Insurance, Department of Health and managed by the National Health Research Institutes. The interpretation and conclusions contained herein do not represent those of the Bureau of National Health Insurance, Department of Health or National Health Research Institutes. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.