Bladder Cancer: Who's at Risk?
In 1997, Joseph Binard, M.D., retired Department of Veterans Affairs (VA) chief of SCI Services in Tampa, asked the Eastern Paralyzed Veterans Association (EPVA) and the Paralyzed Veterans of America (PVA) for support to conduct a bladder-cancer survey of PVA's members. Since bladder-cancer cases are an increasing problem among people with spinal-cord injury (SCI), Binard believed PVA's members would be an ideal population for significant insights as to the degree of the problem and the implications of VA's current clinical bladder-management strategies.
About 80% of bladder-cancer cases in the United States are attributed to exposure to cigarette smoking, chemicals, and ionizing radiation, including ultraviolet. Viruses cause cancer in animals and are associated with some human cancers. The high incidence of various kinds of cancer in certain families implies a genetic susceptibility-but this has not yet been shown in people with SCI and bladder cancers.
In the United States, all forms of cancer are second only to heart disease as a mortality cause. Bladder cancer is the most common urinary-tract malignancy. It occurs 2.3 times more often in men than in women and is more prevalent in urban settings than rural. The majority of bladder malignancies are transitional cell carcinomas; a smaller proportion are squamous cell carcinomas or adenocarcinomas. Veterans with spinal-cord conditions (SCC)-like traumatic SCI and multiple sclerosis (MS)-could be at high risk for bladder cancer due to the frequency of urinary-tract maladies among this male-dominated population.
Despite current research literature suggesting strong links between bladder cancer and people with SCC, nothing published speaks specifically about veterans with SCC. Dr. Binard's previous collaborative research and PVA's 1998 Membership Survey of Department of VA Healthcare Utilization concurred with Binard's hypothesis that veterans with SCC may be at great risk and a new study was needed.
The survey's investigative team, led by Dr. Binard, included Dr. Dirk DeRidder, University Hospitals, Leuven, Belgium; Roy Ippolito, EPVA associate executive director for administration and communications; and PVA Health Policy Department's William Baughman and Thomas Stripling.
The survey shows an inverse relationship between hand dexterity and catheterization method. People who have normal hand function and use a catheter are more likely to use the intermittent type. Individuals who cannot do most tasks requiring hand dexterity use suprapubic catheterization more than expected.
Does level of hand function determine the drainage-method type? Is this practice acceptable? Do health providers determine the method or is it personal choice?
Survey respondents shared personal information about many aspects of daily life. An important one was time. This factor plays a large role in the frequency of all types of cancer. The longer people live, the greater their chance for developing cancer. The length of time people engage in risky behavior, knowingly or unknowingly, relates directly to their chance of developing cancer.
The survey attempted to assess and adjust for the length of time people have had an SCC and engaged in risky behaviors such as smoking and different bladder-drainage systems. This is a measure of how long a person's bladder function may be compromised and, hence, subject to an adverse biologic environment-which in turn may increase the risk of bladder cancer.
Bladder Drainage Methods
Catheter use has been implicated in bladder cancer. Survey results suggest that high-risk-behavior respondents-i.e., older men, smokers, and those with frequent urinary maladies-routinely use catheters, which could be risky. The survey cannot enlighten us as to the degree to which clinicians alert catheter users to any risks.
Some catheter use cannot be avoided. It may replace other risky behaviors or enable people to more freely participate in work or other lifestyles. Drainage methods vary widely.
Odds ratios tell the relationship of bladder cancer to risky behavior. The exposure group includes people who have used a risky behavior. The outcomes group has two categories-cases are those who have bladder cancer or polyps; controls are those who have not had bladder cancer or polyps.
Involvement with risky behaviors is compared between cases and controls. The odds ratio is expressed in terms of a value compared to "1." For example, if more cases of bladder-cancer respondents report having used a suprapubic catheter as the initial drainage method than controls of respondents without bladder cancer, the odds ratio would have a value greater than one. The odds ratio for use of condom catheters between cancer survivors and controls is 0.6. Therefore, condom catheters carry no risk for people regarding developing bladder cancer, while suprapubic and indwelling urethral ones do have a risk (almost two times that of other methods).
[There is] a high correlation between indwelling urethral-catheter use and developing bladder cancer. Historical use of indwelling urethral catheters leads to a 2.6-times greater chance of developing bladder cancer than not having used them.
Odds ratios for sphincterotomies and surgical urinary diversion methods need further interpretation and investigation. The odds ratio for intermittent catheterization use is found to be 0.5 in this study. This is contrary to the relationships for suprapubic and indwelling urethral catheters. Biologic and physical attributes specific to and differences between the types of catheters might explain these contrary findings. Intermittent-catheter use may allow complete drainage of urine from the bladder. Complete voiding will decrease the chance of infection and irritation to the biological environment and perhaps decrease the risk of developing polyps or cancer.
The high odds ratios for sphincterotomies and surgical urinary diversions can be attributed to not knowing whether the drainage method corrected a bladder-cancer problem. When a group of people is asked to respond to a survey at a given point in time, we cannot assume the sequence of events happened in a desirable/predictable way. We cannot determine from this survey whether the development of cancer has preceded a sphincterotomy/surgical diversion or vice versa. Therefore, to continue this analysis, additional healthcare data is necessary.
The survey faces two immediate questions: We want to know more about PVA members who did not respond to the survey, for perhaps there are bladder cancer deaths among them. And, we wish to know more regarding VHA medical services received by PVA members who reported having or having had bladder cancer.
William A. Baughman is a health systems analyst and Thomas E. Stripling is senior health-data analyst at the Paralyzed Veterans of America National Office, in Washington, D.C. The Health Policy Department keeps a careful eye on the major healthcare changes taking place and charts a path to make certain PVA members get the specialized health services they need.
Contact the authors at the PVA Health Policy Department, (800) 424-8200 / (202) 872-1300. For the complete version of this article, including resources, call PVA Publications at (888) 888-2201 and order the April 2000 PN/Paraplegia News.
Bladder Cancer: Who's at Risk?
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