Effect of TNF inhibitors on the risk of cancer recurrence in patients with ankylosing spondylitis: a nested case-control study

Objective To investigate the effect of tumour necrosis factor inhibitors (TNFi) on the risk of cancer recurrence in patients with ankylosing spondylitis (AS) and a history of cancer. Methods We conducted a nested case-control study using a cohort derived from a nationwide database. The cohort consisted of patients with AS and a history of cancer after AS diagnosis. We determined cases of cancer recurrence and selected controls at a ratio of 1:1, matched for age, sex, date of index cancer diagnosis, and follow-up time. Multivariable conditional logistic regression analysis was used to assess the effect of TNFi exposure on the risk of cancer recurrence. Results A total of 2,574 patients with AS and a history of cancer were included in the cohort. Among these, cancer recurred in 394 (15.3%) patients. The incidence rate of cancer recurrence was 4.87 (95% confidence interval [CI] 4.40–5.34)/100 person-years. From this cohort, 254 cases and age-, sex-, index date-, and follow-up time-matched 254 controls were included for the nested case-control study. The proportion of patients exposed to TNFi did not differ between the cases and controls (24.8% vs. 24.4%, p = 0.918). In the multivariable conditional logistic regression analysis, TNFi exposure was not associated with an increased risk of cancer recurrence (adjusted odds ratio 1.157, 95% CI 0.734–1.825, p = 0.531). Conclusion TNFi exposure was not associated with an increased risk of cancer recurrence in patients with AS. Our findings suggest that TNFi may be used with caution in patients with AS and a history of cancer.