No associated increase in short-term malignancy risk with biologic therapy for rheumatoid arthritis

Biologic therapy does not appear to increase risk for malignancy in patients with rheumatoid arthritis, according to a new study.

Researchers performed a meta-analysis of randomized, controlled trials published through July 9, 2012, that evaluated abatacept, adalimumab, anakinra, certolizumab, etanercept, golimumab, infliximab, rituximab and tocilizumab in patients with rheumatoid arthritis and compared their safety with that of placebo or traditional disease-modifying antirheumatic drugs. Included studies were also required to have a follow-up of at least 24 weeks. The results of the meta-analysis appeared in the Sept. 5 Journal of the American Medical Association.

Overall, 63 randomized, controlled trials involving 29,423 patients were included in the analysis. A total of 15,989 patients received biologic therapy plus methotrexate with or without disease-modifying antirheumatic drugs, 3,615 received biologic therapy alone, and 9,819 were controls. Two hundred eleven malignancies developed, of which 118 were solid tumors, 48 were skin cancer, 14 were lymphomas, five were hematologic nonlymphomas and 26 were unspecified. During the first year of therapy, the incidence rates for malignancy were 0.77% in patients receiving biologic therapy plus methotrexate, 0.64% in patients receiving biologic therapy alone, and 0.66% in controls. No statistically significant risk for malignancy was found.

The authors noted that they could not always assess risk for bias, that their data abstraction was not blinded, and that most of the included trials were industry-funded, among other limitations. However, they concluded that patients with rheumatoid arthritis receiving biologic therapy do not appear to have an increased risk for malignancy in the first 24 weeks of therapy. They called for additional reviews of observational studies to help establish long-term risk.

“Although the findings suggest that [biologic response modifiers] may be generally safe with respect to risk of malignancy in the short term, the risk of recurrence in patients with [rheumatoid arthritis] with history of cancer or cancer risk factors remains unknown,” they wrote.