MONDAY, Feb. 13 (HealthDay News) — The cancer rate in children with juvenile arthritis is four times higher than in other children, a new study says.
This increased risk of cancer isn’t necessarily linked to arthritis treatments, such as tumor necrosis factor (TNF) inhibitors, according to the study published online Feb. 13 in the journal Arthritis & Rheumatism.
In the United States, TNF inhibitors carry a “black box” warning about the potential cancer risk associated with the drugs.
In this study, the researchers analyzed 2000-2005 Medicaid data from more than 7,800 children with juvenile arthritis and comparison groups of about 650,000 children with asthma and nearly 322,000 children with attention-deficit hyperactivity disorder (ADHD).
The incidence rate of probable and highly probable cancers in children with juvenile arthritis was 4.4 times higher than in the other groups of children.
Juvenile idiopathic arthritis (JIA) in children is a general term covering different types of chronic arthritis. Symptoms, similar to adult arthritis, include joint pain, swelling, tenderness and stiffness.
“While our findings show children with [juvenile idiopathic arthritis] have a higher incidence of cancer compared to peers without JIA, the greater frequency of malignancy does not appear to be necessarily associated with treatment, including use of TNF inhibitors,” concluded Dr. Timothy Beukelman, of the University of Alabama at Birmingham, in a journal news release.
“This highlights the critical importance of appropriate comparator groups when evaluating the safety of new medications. Further confirmation of our findings with large-scale and long-term investigation of the association between cancer and [juvenile arthritis] and its treatment is needed,” he added.
Most of the children with juvenile arthritis in the study were treated with injections of etanercept, a soluable TNF-receptor blocker. Other anti-TNF drugs that work by different mechanisms may yield different results, Dr. Karen Onel and Dr. Kenan Onel from the University of Chicago noted in an accompanying journal editorial.
But, “By focusing on the possible cancer risk associated with the use of TNF inhibitors, the underlying cancer risk associated with [juvenile arthritis] may have been understated, and it is important to make patients, families and physicians aware of the possible late consequences of this disease,” they added in the news release.
More information
The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about juvenile arthritis.