Survivors of childhood cancers treated with cyclophosphamide more likely to develop bladder cancer

Survivors of childhood cancers treated with the chemotherapy drug cyclophosphamide were five times more likely to develop bladder cancer later in life than the general population. Results of this new research from the United Kingdom were presented today during the Annual Scientific Meeting of the American Urological Association (AUA). Survivors originally diagnosed at zero to four years of age and those diagnosed with retinoblastoma, leukemia and non-Hodgkin’s lymphoma were at a particularly higher risk. Researchers presented their findings to the media during a special press conference on May 19, 2008 at 3:00 p.m.

Researchers analyzed British Childhood Cancer Survivor Study (BCCSS) records of patients diagnosed under the age of 15 with leukemia, non-Hodgkin’s lymphoma, retinoblastoma or soft tissue sarcoma and subsequently treated with cyclophosphamide or radiotherapy. Patients in the study cohort had a survival rate of at least five years. These data were compared to records from the National Health Service Central Register through 2004 to identify patients who subsequently developed bladder cancer to determine whether treatment choice could be associated with future bladder cancer development.

Bladder cancer was found in 19 patients (5.3 times what was expected), with a mean follow up (post-five-year survival) of 18.9 years. Further analysis of follow-up intervals (20, 30, 40 and 50 years post-five-year survival) indicated that the risk of developing bladder cancer increases with time. The cumulative percentage of survivors diagnosed at 20, 30, 40 and 50 years was 0.02 percent, 0.08 percent, 0.37 percent and 0.71 percent, respectively.

Cyclophosphamide, an immunosuppressive drug used to treat several types of cancer, is known to cause bladder damage that predisposes patients to subsequent bladder cancer.

Source: American Urological Association