Biologics' Cancer Risks Unclear in JIA

Mannion ML, Beukelman T. Risk of malignancy associated with biologic agents in pediatric rheumatic disease.Current Opinion in Rheumatology. (2014) 26:538-542. doi: 10.1097/BOR.

The background risk of cancer in juvenile idiopathic arthritis (JIA) may be two to four times greater than for the general population, but a new review finds that such cases are rare -- and do not appear to be linked solely to use of biologics.

The review by researchers at the University of Alabama at Birmingham comes in response to federally-mandated cancer warnings for tumor necrosis-alpha (TNFα) blockers in children.

Although there may be a five-fold rise in the rate of lymphoma with etanercept (Enbrel) in JIA, there’s no increase in the overall rate of malignancies among those using the drug, the review notes.

If TNF blockers influence the cancer risk for children with JIA, the effect is likely to be low or modest, it adds.

Adults taking TNF inhibitors for rheumatoid arthritis (RA) are known to have less than a 1% increased risk of cancer, especially lymphoma, and a doubled risk of melanoma. However, the increased risk of cancer in these patients is generally related to disease severity.

The review also notes that childhood-onset systemic lupus erythematosus (SLE) is “likely associated” with an increased malignancy risk, as is SLE in adults. But it stresses that the impact of biologic drugs in children is not known.

The US Food and Drug Administration (FDA) agency issued a report in 2009 citing increased rates of lymphoma and other malignancies associated with biologics after 30 months of treatment.

As a result, the agency mandated a special “boxed” warning on cancer risk for TNFα inhibitors in children and adolescents who are taking the drugs for juvenile rheumatoid arthritis, Crohn’s disease, and other inflammatory diseases.