San Francisco, CA, May 30, 2010–Arsenic exposure is a known risk factor for bladder cancer. Bladder cancer patients who have been exposed to arsenic in their drinking water may be at an increased risk of developing more aggressive forms of the disease, according to researchers. A new study from Santiago, Chile will be presented on Sunday, May 30, 2010 during a special press conference at 10:30 a.m. PDT during the 105th Annual Scientific Meeting of the American Urological Association (AUA).
Arsenic is a notoriously poisonous metalloid that is found in nature. Arsenic compounds are commonly used in herbicides and pesticides, and in metal alloys. A number of areas around the world, including the U.S. Southwest, have groundwater with naturally high levels of the element.
Researchers in Chile reviewed bladder cancer trends from a region of northern Chile where, between 1955 and 1989, approximately 400,000 inhabitants were exposed to extreme levels of arsenic in drinking water. Researchers gathered information on arsenic levels, bladder cancer mortality and hospital admissions for the period and compared the data to country-wide statistics. After more than three decades of exposure to high levels of arsenic, concentrations normalized in 1989 and have remained stable over the past two decades.
Mortality rates increased between 15 and 25 years after the high levels of exposure began. They rose from 3 and 2 in 100,000 for men and women, respectively, in 1955 to 6 and 6 per 100,000 in 1977. This increase has continued even after arsenic levels normalized. Over the past 20 years, mortality peaked at 22 per 100,000 men and 18 per 100,000 women. These mortality figures are high compared to areas of the country without an increased risk for arsenic exposure.
Researchers found not only an increased mortality rate but also a lower overall age at time of cancer-specific death compared to people living in unaffected parts of the country. Hospital admission rates in the affected area were also significantly higher.
These data show that, despite control of arsenic in drinking water, the effects of the toxin are long-lasting.
“This is a major study highlighting the potentially adverse effects of toxins like arsenic in the environment that may lead to increased rates of urologic cancer, sometimes many years after the exposure. It is one more piece of a growing literature which emphasizes the effects that environmental exposures may have on urologic cancer and disease” said Anthony Y. Smith, MD, a spokesperson for the AUA.
NOTE TO REPORTERS: Experts are available to discuss this study outside normal briefing times. To arrange an interview with an expert, please contact the AUA Communications Office at the number above or e-mail Communications@AUAnet.org.
About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the American Urological Association is the pre-eminent professional organization for urologists, with more than 16,000 members throughout the world. An educational nonprofit organization, the AUA pursues its mission of fostering the highest standards of urologic care by carrying out a wide variety of programs for members and their patients.
Wendy Isett, AUA