Patients with rheumatoid arthritis who receive treatment with tumor necrosis factor inhibitors (TNFi), tocilizumab, abatacept, or rituximab do not appear to be at increased risk for overall cancer, according to a study published in JAMA Internal Medicine.
In this register-based prospective cohort study conducted in Sweden from 2006 to 2015, researchers identified a total of 15,129 initiations of a TNFi as a first or second biological disease-modifying antirheumatic drug (bDMARD), 7405 initiations of other bDMARDs (tocilizumab, abatacept, and rituximab), and 46,610 initiations of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).
The researchers found no statistically significant difference in the risk for malignant neoplasms in patients initiating a first or second TNFi, tocilizumab, abatacept, rituximab, or csDMARDs.
The only exception was the observation of an increased risk for squamous cell skin cancer in patients treated with abatacept. Although this may be a chance finding based on 17 events, the association of squamous cell skin cancer and immune incompetence has been well established.
Among other limitations of the study was the relatively recent use of non-TNFis for treatment of rheumatoid arthritis, which limits the follow-up time and statistical power to less than 10 years. In addition, the results of this study do not rule out the possibility of increased risk for specific cancer types or those that require a longer time to manifest.
The investigators concluded that “treatment with TNFi (as first or second bDMARD), tocilizumab, abatacept, or rituximab does not seem to increase the total occurrence of malignant neoplasms, nor did we find any signals of increased risks for specific cancer types, with 1 exception, that calls for replication.”
Wadström H, Frisell T, Askling J, for the Anti-Rheumatic Therapy in Sweden (ARTIS) Study Group. Malignant neoplasms in patients with rheumatoid arthritis treated with tumor necrosis factor inhibitors, tocilizumab, abatacept, or rituximab in clinical practice: a nationwide cohort study from Sweden [published online September 18, 2017]. JAMA Intern Med. doi:10.1001/jamainternmed.2017.4332