Alan M. Nieder

Modifiable risk factors for bladder cancer have been identified, ie tobacco and chemical exposure. We identified high risk bladder cancer areas and risk factors associated with bladder cancer clusters in Florida using individual and area based data. Spatial modeling was applied to 23,266 early and advanced bladder cancer cases diagnosed between 1998 and 2002 in Florida to identify areas of excess bladder cancer risk. Multivariable regression was used to determine whether sociodemographic indicators, smoking history and proximity to known arsenic contaminated drinking water well sites were associated with bladder cancer diagnosis in a specific area (cluster). A total of 25 clusters were found to have a higher than expected bladder cancer rate, including 13 and 12 of early and late stage disease, respectively. Urban white patients were more likely to live in an advanced bladder cancer cluster. Advanced bladder cancer cluster membership was associated with living in close proximity to known arsenic contaminated drinking water wells. There are multiple areas of early and late stage bladder cancer clusters in Florida. Individuals in an advanced bladder cancer cluster tended to live close to arsenic contaminated wells. Increased evaluation of potentially contaminated well water is warranted in these high risk areas. Targeted bladder cancer public awareness campaigns, smoking cessation support and potentially targeted screening should also be considered in communities at increased risk for bladder cancer. Our analytical approach can also be used by others to systematically identify communities at high risk for bladder and other cancers.

Pre-prostate specific antigen era series demonstrated an increased risk of bladder cancer and rectal cancer in men who received radiotherapy for prostate cancer. We estimated the risk of secondary bladder cancer and rectal cancer after prostate radiotherapy using a contemporary population based cohort. We identified 243,082 men in the Surveillance, Epidemiology and End Results database who underwent radical prostatectomy or radiotherapy for prostate cancer between 1988 and 2003. We estimated the incidence rate, standardized incidence ratio and age adjusted incidence rate ratio of subsequent bladder cancer and rectal cancer associated with radical prostatectomy, external beam radiotherapy, brachytherapy, and a combination of external beam radiotherapy and brachytherapy. The relative risk of bladder cancer developing after external beam radiotherapy, brachytherapy and external beam radiotherapy-brachytherapy compared to radical prostatectomy was 1.88, 1.52 and 1.85, respectively. Compared to the general United States population the standardized incidence ratio for bladder cancer developing after radical prostatectomy, external beam radiotherapy, brachytherapy and external beam radiotherapy-brachytherapy was 0.99, 1.42, 1.10 and 1.39, respectively. The relative risk of rectal cancer developing after external beam radiotherapy, brachytherapy and external beam radiotherapy-brachytherapy compared to radical prostatectomy was 1.26, 1.08 and 1.21, respectively. The standardized incidence ratio for rectal cancer developing after radical prostatectomy, external beam radiotherapy, brachytherapy and external beam radiotherapy-brachytherapy was 0.91, 0.99, 0.68 and 0.86, respectively. Men who receive radiotherapy for localized prostate cancer have an increased risk of bladder cancer compared to patients undergoing radical prostatectomy and compared to the general population. The risk of rectal cancer is increased in patients who receive external beam radiotherapy compared to radical prostatectomy. Patients should be counseled appropriately regarding these risks.