Cancer risks in patients with ankylosing spondylitis and the effects of biologic agents: a population-based study.

ABSTRACT

OBJECTIVES: To conduct a population-based analysis of the malignancy risks of patients with ankylosing spondylitis (AS). METHODS: A total of 1,796 patients with AS and 7,184 age- and sex-matched controls (14 ratio) were selected from the Korea National Health Insurance Service-National Sample Cohort database. Data of patients diagnosed with AS (code M45) according to the International Classification of Diseases (ICD) 10th edition, between 2002 and 2019, were reviewed. These data were extracted based on the ICD codes assigned to cancer patients. RESULTS: Cancer developed in 168/1,796 patients (9.3%) after the AS diagnosis. After adjusting for confounders, the cancer risk of patients with AS was not significantly increased compared with that of controls (adjusted hazard ratio [HR] 1.1; 95% confidence interval [CI] 0.93-1.31). However, the risks for upper gastrointestinal (GI) cancer (adjusted HR 1.51; 95% CI 1.07-2.12) and haematologic malignancy (adjusted HR 2.36; 95% CI 1.2-4.65) were significantly higher in patients with AS than in controls. There were no significant differences in the risks for other major cancers between patients with AS and controls. Regarding medication for AS, the HR of upper GI cancer was higher in patients with AS compared with controls (adjusted HR 1.51; 95% CI 1.00-2.29). CONCLUSION: The overall cancer risks in patients with AS were not significantly different compared with the controls. However, while the effect of non-steroidal anti-inflammatory drugs on upper GI cancer cannot be ruled out, patients with AS exhibited a significant increase in the risk of both upper GI cancer and hematologic malignancy.