Popular rheumatoid arthritis drugs Cimzia, Enbrel, Humira, Remicade, and Simponi all play a major role in helping fight against rheumatoid arthritis by inhibiting a natural protein called tumor necrosis factor alpha (TNFa) however a recently revealed study has found that the protein also plays another important role, fighting off cancer.
During clinical testing the protein blocking drugs showed no signs of increase cancer risk however the long term effects of blocking the protein were not discovered at those times.
In 2006 a study published in the Journal of the American Medical Association found a correlation between the protein blocking drugs and increased cancer risk however the study could not be duplicated and was later abandoned.
Speaking to WebMD University of Miami rheumatologist Ozlem Pala, MD says:
“We are more or less sure now we won’t see a really big increased risk of cancer with these medicines,” while they add, “It is definitely better than what we were afraid of. But we still have to be really cautious about the possibility of cancer risk [in patients on TNF inhibitors].”
A recent analysis showed that the most likely culprit would be skin cancer while other forms of cancer did not appear to increase in likelihood.
Researchers also found an increased risk of melanoma in patients on TNF inhibitors however they say the findings are weak and could have been due to chance occurrences.
According to another one of the study’s researchers anti-TNF drugs weaken part of the immune system and are known to increase the risk of skin cancers.
The group warns that doctors should be cautious in prescribing the drugs to anyone with a high lifetime exposure to sunlight and they note that non-melanoma skin cancers are easily treatable and therefore less of a concern for patients attempting to treat painful rheumatoid arthritis.
The group also reveals that since Cimzia and Simponi were only approved two years ago they were not included in their long-term study.
The full study can be found in the September 8 online issue of Annals of Rheumatic Diseases