Tumor necrosis factor inhibitors used to treat rheumatoid arthritis have been linked to increased risk of skin cancer.
A review of previously published studies has found an apparent link between tumor necrosis factor (TNF) inhibitors used to treat rheumatoid arthritis (RA) and an increased risk of skin cancer. The research was published online in Annals of the Rheumatic Diseases earlier this month.
RA itself has been linked to an increased risk of lymphoma and lung cancer, as well as a reduced risk of other cancers, including bowel and breast cancer. The new analysis looks at the results of 21 studies conducted between 1998 and 2010 and eight conference abstracts, all of which included data on rates of cancer among RA patients taking TNF inhibitors, which act on the immune system. In all, the studies analyzed included data on more than 40,000 patients and almost 150,000 total patient years of exposure to the drugs.
The pooled risk from seven studies that looked at the development of any cancer found negligible or no increased risk overall. Two other studies indicated no evidence of increased risk of cancer, though they did find that patients who had previously had cancer were more likely to experience a recurrence. But four studies found that patients taking TNF inhibitors were 45% more likely to develop non-melanoma skin cancers, and two studies showed that patients taking TNF inhibitors were 79% more likely to develop a melanoma than patients not taking the drugs.
"This systematic review and meta analysis provides reassurance to physicians and patients that the treatment of [rheumatoid arthritis] with TNF inhibitors does not increase the risk of malignancy, particularly lymphoma," write the authors. "However, it does appear to increase the risk of skin cancer, including melanoma.”