Long-term safety of Infliximab for the treatment of inflammatory bowel disease: does blocking TNFα reduce colitis-associated colorectal carcinogenesis?

We read with interest the article by Fidder et al 1 reporting, in a single-centre cohort study, the frequency of severe adverse events (SAEs) in 734 infliximab- and 666 non-infliximab treated patients with inflammatory bowel disease (IBD) followed-up in the long term (median 58 and 144 months, respectively). While no differences between the two groups were detected in terms of SAEs, mortality, infection rate and malignancies, we do believe that the type of cancer observed deserves further consideration. A comparable cancer incidence was detected in the two groups, confirming previous studies.2 3 However, while in the non-infliximab-treated group 8 out of the 666 (1.2%) patients had a newly diagnosed colorectal cancer, no patients in the infliximab group had a new diagnosis of colorectal cancer (0%) during the study period. In the infliximab group, one metastatic adenocarcinoma of unknown origin was, however, detected in one …