Abstract
Biologics has been widely used in the treatment of rheumatoid arthritis. We aimed to determine whether etanercept, a TNF-α inhibitor (TNFi) that is used to treat patients with rheumatoid arthritis (RA), affects cancer risk.This retrospective matched cohort study used data in the Registry of Catastrophic Illness Database in Taiwan from January 1, 1996 to December 31, 2010. RA, all-cancer, and solid cancer were defined using International Classification of Disease codes (ICD-9-CM 714.X, 140-208, and 140-199, respectively). Cox proportional hazard modeling was used to estimate the hazard ratio (HR) of cancer in all TNFi-treated RA patients, with a focus on the risk in the etanercept-treated patients, after adjusting for comorbidities and concomitant medication.In this Taiwanese dataset, there were 1111 TNFi-treated RA patients and 16,812 RA patients who were naive to all biologics identified. Among the 1002 pairs of etanercept-treated and biologic-naive patients who were matched 1-to-1 for age, gender, RA duration, methotrexate-use, and index date of TNFi prescription, the mean age was 48.9 ± 15.0 years. The highest proportion of patients was in the age subgroup of 30 to 60 years (63.8%). Most patients (77.2%) were women. The mean RA duration before etanercept treatment was 2.0 ± 1.5 years. During a mean 2.1 years of observation, etanercept was associated with significant risk reduction for all-cancer (HR 0.59, 0.36-0.98) and solid cancer (HR 0.46, 0.27-0.79) relative to the matched biologic-naive patients.The current study explored the safety profile of TNFi and identified a potential benefit of etanercept on the incidence of all-cancer and solid cancer in RA patients.