A new study from the University of Michigan Comprehensive Cancer Center finds that blacks with bladder cancer have the worst prognosis and are 35 percent more likely to doe than whites. The study involved 93,093 people with bladder cancer and found that blacks with advanced cancer had aggressive cancers and were more likely to succumb to it.
Results of the study appear in the September issue of the Journal of Urology.
Using data from the Surveillance, Epidemiology and End Results registry, a population-based cancer registry maintained by the National Cancer Institute, researchers looked at patients diagnosed with bladder cancer between 1973 and 1999. The large timeframe allowed the researchers to review trends in five-year intervals.
They found that over time, more patients were diagnosed with early tumors that had not spread rather than advanced disease. But in the most recent time interval, 80 percent of white patients were diagnosed with early stage cancer while only 68 percent of black patients were. Black women had the highest proportion of advanced tumors at all time intervals.
"Many groups speculate that the racial disparity in bladder cancer is a result of blacks being diagnosed with more advanced disease. We found that while there is disparity in the stage at diagnosis, there have also been some improvements. Black patients diagnosed with bladder cancer in more recent years have a higher rate of early stage disease than those diagnosed in the earlier years," says study author Cheryl Lee, M.D., director of the bladder cancer program at the U-M Comprehensive Cancer Center and associate professor of urology at the U-M Medical School.
"The problem is we are not seeing the clinical benefit of this as black patients are still dying from bladder cancer at a higher rate than white patients," Lee adds.
Bladder cancer is twice as common in whites as it is in blacks, but black people have lower survival rates. In this study, 24 percent of the black patients died of bladder cancer while 15 percent of the white patients did. Even when the researchers compared only the patients with early stage disease, blacks had lower survival rates than whites.
The degree to which the tumor has spread affects treatment options as well as survival. The researchers found fewer black patients had been treated with minimally invasive surgery and more underwent open surgery to remove their bladder. Black patients were also more likely to receive radiation therapy along with surgery.
In addition, the researchers found black patients tended to have more aggressive tumors. Most notably, the majority of black women had aggressive tumors. From 1992-1999, black women were 15 percent more likely than white men and women and 11 percent more likely than black men to have an aggressive type of bladder cancer.
"Survival outcomes in white patients who underwent surgery were significantly better than that in black patients who underwent surgery for similar types of early stage cancer. This continued disparity suggests that factors other than tumor grade, stage or treatment type are influencing bladder cancer survival," Lee says.