Cancer is a common event in patients with rheumatic diseases. In some cases, the disease, its risk factors, or its treatment could play a role in favoring cancer. This article analyzes the current knowledge on the risk of malignancy associated with biologics in rheumatic diseases and discusses some methodological issues to be considered when evaluating the association between disease, treatments, and the risk of cancer. This article focuses on the risk of overall malignancy but also of skin cancer, lymphoma, and recurrent cancer associated with all biologics marketed for the treatment of rheumatic diseases.
The risk of cancer with anti–tumor necrosis factor (anti-TNF) has been extensively studied and the data are reassuring, showing no evidence overall of an increased risk of cancer.
It is highly probable that anti-TNF is associated with an increased risk of nonmelanoma skin cancers, but possibly no different from that of other classic disease-modifying antirheumatic drugs.
The risk of lymphoma does not seem to be increased with anti-TNF, but more data are required to analyze a possible dose effect and differential risk depending on the mechanism of action.
Regarding other biologics, data are too few to draw any firm conclusion, although rituximab has reassuring data from its hematologic indications.