While a diagnosis of juvenile idiopathic arthritis, pediatric inflammatory bowel disease, or pediatric plaque psoriasis increases the risk of cancer, use of TNF inhibitors do not seem to significantly affect malignancy rates, a study has found.
The study, “Risk of malignancy associated with paediatric use of tumour necrosis factor inhibitors,” was published in the journal Annals of the Rheumatic Diseases.
Researchers set out to assess the risk of cancer developing in children with autoimmune disorders, including juvenile idiopathic arthritis, who were treated with TNF inhibitors.
Tumor necrosis factor (TNF) is a protein that promotes inflammation. TNF inhibitors act to block or reduce this protein, decreasing inflammation and preventing damage to joints.
Data was analyzed from children with juvenile idiopathic arthritis, pediatric inflammatory bowel disease, and pediatric plaque psoriasis, based on health insurance claims in the U.S. between 2000 and 2014.
Researchers used data from 15,598 children (with an average age of 13.4 years) who used TNF inhibitors, followed for an average of two years, and 73,839 children (average age of 11.6 years) who did not use TNF inhibitors, followed for an average of 1.7 years.
Of the children treated with TNF inhibitors, 37% used etanercept (sold under the brand name Enbrel), 34% infliximab (sold under the brand names Remicade, Remsima, Inflectra), 29% adalimumab (sold as Humira, among others), 2% certolizumab (sold as Cimzia), and 1% golimumab (Simponi).
Researchers identified 15 malignancies among children using TNF inhibitors, with 2.9 times greater risk of developing cancer during roughly two years of follow-up than the general population. There were six cases of lymphoma, three of brain tumors, two leukemia, two malignant melanoma, and one bone and one liver cancer.
Among children who did not take TNF inhibitors, 42 malignancies were identified.
After adjusting the results for several parameters, children who were treated with TNF inhibitors were found to be 1.58 times more likely to develop cancer than those who were not. For lymphoma, however, the risk was 2.64 times higher for users of TNF inhibitors.
The authors pointed out that the U.S. Food and Drug Administration had previously reported an 18-fold higher risk of lymphoma in children who received Remicade.
They also noted that the follow-up time in the study was short, and that an association between long-term TNF inhibitor use and cancer could not be assessed.
“The amount of observable follow-up after TNFi [TNF inhibitor] exposure was limited,” the team wrote. “A possible association between long-term TNFi use and malignancy could not be adequately evaluated. Many of these challenges may be partially addressed with long-term data from large prospective observational registries.”
Nonetheless, based on the results, the team concluded that children diagnosed with juvenile idiopathic arthritis, pediatric inflammatory bowel disease, or pediatric plaque psoriasis had an increased “risk of incident malignancy and that use of TNFi does not appear to significantly further increase this risk in the first few years after use, with the possible exception of lymphoma.”