In a research study at the University of Dundee, Queen Mary University of London and the Wellcome Sanger Institute, a drug, by the name of azathioprine, which is used to treat inflammatory bowel disease (IBD), arthritis and vasculitis as well as preventing organ rejection in transplant patients, has been identified as a contributor the development of skin cancer.
Published in Nature Communications, the research identified a `strong case for an association' between azathioprine and a mutation found in a common form of skin cancer known as cutaneous squamous cell carcinoma (cSCC). Previously, it was known that azathioprine leads to a heightened photosensitivity to UVA light. Such sensitivity is believed to be the key behind its contribution to skin cancers. The study found that the use of azathioprine leaves a ‘molecular fingerprint’ in skin cancers, implicating it in cSCC. "We recommend all physicians give appropriate advice on UVA avoidance including year-round sun protection for their patients on azathioprine,” explains Professor of Dermatology--Charlotte Proby in the School of Medicine at Dundee.
However, the research team is not necessarily promoting the withdrawal of azathioprine. "As with all medications the risks must be balanced against the benefits, particularly with the need to treat potentially life-threatening diseases with an effective drug," explains Proby. “It is important that sun protection, skin surveillance and early diagnosis/lesion removal are part of the routine management of patients on azathioprine."
cSCC is a commonly diagnosed skin cancer. "It's important to protect your skin from the sun when it's strong, especially if you burn easily or are taking medications which make you more sun-sensitive. The most effective protection is to spend time in the shade and cover up with a hat, long-sleeved top, and sunglasses. For the bits you can't cover, use sunscreen with at least 4 stars and SPF 15 or higher for protection against both UVA and UVB rays,” says Sarah Lowes of Cancer Research UK.
The research also revealed the molecular nature of cSCC which highlighted the potential targets that may be developed for future treatments.