Risk of Cancer Recurrence Among Individuals Exposed to Antitumor Necrosis Factor Therapy A Systematic Review and Meta-Analysis of Observational Studies

Background: Patients with immune-mediated disorders such as ankylosing spondylitis, inflammatory bowel disease, psoriasis and rheumatoid arthritis are increasingly treated with tumor necrosis factor (TNF) inhibitors. The safety of anti-TNF therapy in patients with a history of cancer requires further evaluation. We conducted a systematic review and a meta-analysis of observational studies including patients with a history of cancer exposed to anti-TNF therapy assessing for a risk of new cancer or cancer recurrence. Materials and Methods: A computerized literature search of MEDLINE, Google scholar, and Cochrane Database of Systematic Reviews was performed through September 1, 2015. Study characteristics, quality, and risk of bias were assessed. Random-effects model meta-analyses were used to estimate the risk of new cancer development or cancer recurrence. Results: Nine English-language observational studies including patients with a history of cancer and exposed to anti-TNF therapy were idenitifed. The pooled incidence rate ratio of new or recurrent cancer among individuals with a history of cancer exposed to anti-TNF therapy was not significantly different compared with control therapies (incidence rate ratio, 0.90; 95% confidence interval, 0.59-1.37). Subgroup analyses were performed according to disease type, underlying cancer diagnosis, time to initiation of anti-TNF therapy and study quality. Heterogeneity of study populations, heterogeneity of the included cancer subtypes and utilization of observational studies limits the study quality. Conclusions: The risk of new cancer or cancer recurrence among patients with a history of cancer and use of anti-TNF therapy is similar to the risk with nonbiological disease modifying therapies. These results support the use of anti-TNF medications in select populations despite prior diagnosis of cancer.