Abstract

Objective: An increased risk for certain types of malignancies has been reported in rheumatoid arthritis (RA) patients. Comparable risks may exist in juvenile-onset arthritis due to its pathophysiological similarities with adult rheumatoid arthritis. Our objective was to investigate the relationship between juvenile-onset arthritis and risk of malignancy.
Methods: A systematic review of the published literature was performed. Articles reporting data concerning the observed cancer rates in patients with juvenile-onset arthritis versus the general population rates were further assessed. The standardized incidence ratios (SIR) of observed to expected cases were retrieved from the studies and pooled in order to determine the overall risk of malignancy in patients with juvenile-onset arthritis.
Results: The pooled SIR for overall cancer was 1.4 (95% Confidence Interval, CI 1.2-1.7). However, study data were not homogenous: certain studies showed a significantly increased risk of malignancy overall in juvenile-onset arthritis, but others showed that there was no significant increase in cancer risk overall. The pooled SIR for hematological malignancies was 1.7 (95% CI 1.2-2.4) across all studies.
Conclusions: Existing data on malignancy risk in juvenile-onset arthritis are conflicting. Additional data are needed in order to definitively establish the presence or absence of an association between juvenile-onset arthritis and cancer risk.