No Added Lymphoma Risk with TNF Inhibitor Use Save

Warnings of cancer, especially lymphoma, have accompanied the development and promotion of tumor necrosis factor inhbitors (TNFi) in the treatment of RA and other inflammatory disorders. All TNF inhibitors carry a black box warning with respect to lymphoma, and the strong association between chronic inflammation and lymphoma in RA is also well known. Nevertheless, there has been concern over whether the drug imposes additional risk.

One could even speculate that TNFi could potentially reduce the risk of lymphoma by reducing ongoing inflammation.

The UK British Society of Rheumatology biologics registry (BSRBR) was established in 2001 to study the safety of TNFi and with the primary aim to determine the relationship between exposure to TNFi and lymphoma risk.

This prospective registry includes a total of  3367 RA patients on conventional DMARDs (csDMARD) and 11,931 treated with TNFi. The TNFi cohort comprised 4144 (35%) patients starting etanercept, infliximab in 3499 (or 29%) and adalimumab in 4288 (36%). The TNFi cohort was younger and comprised more women than those receiving csDMARDs.

After fully adjusting for propensity scores, there was no difference in the risk of lymphoma for those treated wtih TNFi compared with csDMARD (Hazard Ratio 1.00; 95% CI 0.56 to 1.80).

This national prospective study, with over 120000 patient-years of exposure to anti-TNF or csDMARD, did not identify any difference in lymphoma risk when TNFi were added (for up to 8 years) to the standard treatment regimen in RA patients.

This data is consistent with other published data and the biological expectation that disease activity is the primary driver for lymphoma in RA.