RA Study: No increased cancer risk with TNF blockers 18 Sep 2006

Concerns have persisted about a possible association between (TNF) antagonists and the development of cancers in patients with RA.
These drugs have now been in use for about 10 years and 3 years in Australia

According to pooled data for almost 8,000 rheumatoid arthritis (RA) patients there is no increase in haematologic malignancies and solid tumors for those treated with tumour necrosis factor (TNF)-alpha blockers, compared with those prescribed methotrexate.

The authors of this study highlight recent reports describing significant increases in cancer risk, particularly for lymphomas, while others support the safety of the drugs. Therefore, the authors undertook the current study to estimate the association between treatment with biologic disease-modifying anti-rheumatic drugs (DMARDs) and development of cancer in patients with RA.

Researchers from Harvard Medical School identified 7,306 methotrexate users and 1,152 treated with a TNF-alpha blocker (etanercept, infliximab, adalimumab, or anakinra).

After controlling for demographics, cancer risk factors, RA severity, health care utilisation, and other major comorbidities, patients using biologic agents did not have a higher risk for cancer compared with the methotrexate users. This was despite those using TNF-alpha blockers having more severe disease.

“Our data indicate that it is unlikely that RA patients who have received biologic agents have a much greater risk of lymphoproliferative disorders, haematologic malignancies, and solid tumors as compared with methotrexate users.”

However, the authors call for larger studies or longer follow-up cautioning, “despite the use of large combined data sets, studying the effect of an infrequent exposure (biologic DMARDs) on rare diseases (haematologic malignancies) remains a challenge.”

Reference Setoguchi, S. Solomon, D. Weinblatt, M. et al. 2006, ‘Tumor necrosis factor antagonist use and cancer in patients with rheumatoid arthritis’, Arthritis & Rheumatism, vol. 54, pp. 2757-2764.