In a recent study of possible triggers of cancer, scientists identified an increased risk to the bladders of patients taking drugs that suppress the immune system.
The findings came from a population-based, case-control study in New Hampshire.
Dartmouth epidemiologist Margaret R. Karagas and her team examined the long-term use of glucocorticoids by 786 bladder-cancer patients and by 1,083 control subjects.
Doctors commonly prescribe a combination of cytotoxic drugs and glucocorticoids as immunosuppressive therapy to help recipients of transplants avoid rejection of their new organs, and patients with rheumatoid arthritis, asthma, and other conditions often take glucocorticoids.
Previous research has shown associations between such drug therapies and higher risk of skin cancer and lymphoma.
The researchers say that a similar risk for bladder cancer "might indicate the need for closer monitoring of individuals who regularly take glucocorticoids."
The findings appear in the September 2009 issue of the British Journal of Cancer.