A Danish study has found no increase in cancer risk in people taking tumor necrosis factor alpha (TNF-α) inhibitors over a long period. The authors (Ann. Rheum. Dis. 70 (suppl. 3), 410, 2011) cross-referenced data from 5,598 patients included in DANBIO, the national Danish Rheumatological registry set up in 2000 to monitor individuals treated with biologic drugs, with the Danish Cancer Registry. They concluded that, “No overall or specific elevation of cancer risk was observed during up to nine years of follow-up.” The cohort, mainly treated for rheumatoid arthritis with TNF-α blockers Humira (adalimumab), Remicade (infliximab) and Enbrel (etanercept) from 2000 to 2008, will continue to be followed. Given the cytokine's role in immune surveillance for cancer, it was always anticipated that blocking anti-TNF-α might leave patients open to a higher risk of malignancies. This led to black box warnings and, in August 2009, the US Food and Drug Administration (FDA) added specific information about the risk of lymphomas and other rare cancers in pediatric patients. But the overall level of risk remains unclear. As recently as December 2010, a meta-analysis, commissioned by the European Medicines Agency, of 74 randomized controlled trials involving 15,418 patients treated with TNF-α blockers, could neither “refute nor verify” any link. The recent results do not mean TNF-α blockers are in the clear yet. Lead author Lene Dreyer of the Department of Rheumatology at Gentofte University Hospital in Denmark said, “Drugs targeting TNF can influence the development of tumors, although the extent of this impact remains unclear.”