TNFα Blockers May Raise Risk of Malignancies in Children
But association may not be causal, could involve confounding factors
WEDNESDAY, Aug. 4 (HealthDay News) -- Children taking tumor necrosis factor α (TNFα) blockers may be at increased risk for developing malignancies, but confounding factors make it difficult to establish a causal relationship, according to research published in the August issue of Arthritis & Rheumatism.
Due to concerns of a raised risk of malignancies in children using TNFα blockers, Peter Diak, of the U.S. Food and Drug Administration in Silver Spring, Md., and colleagues searched the FDA's Adverse Event Reporting System for malignancies associated with infliximab, etanercept, and adalimumab treatment in children 18 years and younger. They compared infliximab and etanercept reporting rates with the background malignancy rate in the general pediatric population.
The researchers found 48 malignancy reports for children, 31 after treatment with infliximab, 15 after treatment with etanercept, and two after treatment with adalimumab. Half of these cases were Hodgkin's and non-Hodgkin's lymphomas, and the rest consisted of malignancies that included leukemia, melanoma, and solid organ cancers. In a substantial majority -- 88 percent of the cases -- the children were taking other immunosuppressants at the time of treatment. The reporting rates for infliximab were consistently higher than background rates in the general pediatric population for lymphomas and all malignancies; for etanercept, reporting rates were higher than the background rate for lymphomas, but level with background rates for all malignancies.
"There is evidence that treatment with TNF blockers in children may increase the risk of malignancy. However, the cases were confounded by the potential risk of malignancy associated with underlying illnesses and the use of concomitant immunosuppressants; therefore, a clear causal relationship could not be established," the authors write.