Men have a higher incidence of bladder cancer, and a recent lab study finds certain male hormones and hormone receptors may put men at risk.  We’ll talk to a man who was diagnosed with bladder cancer at age 42, and see lab research into the hormonal links to this disease. Bladder Cancer
The American Cancer Society estimates about 68,810 new cases of bladder cancer will be diagnosed in the U.S. this year. The condition is more common in older adults, with 90 percent of cases diagnosed after 55. Bladder cancer is roughly three to four times more common in men than in women. In fact, it’s the fourth most common cancer in American men. The cancer is also twice as common in whites as in blacks.

The biggest risk factor for bladder cancer is smoking. Researchers believe the dangerous chemicals in cigarettes are filtered by the kidneys and collected in urine. The lining of the bladder is exposed to the chemicals in the urine.
Exposure to certain occupational chemicals can increase risk for the same reason. Other risk factors include chronic inflammation of the bladder, personal history of bladder cancer and not drinking enough fluids (which causes urine to remain in the bladder for a longer period of time).

The Role of Hormones
Researchers are not certain why bladder cancer is more common in men than in women. Edward Messing, M.D., F.A.C.S., Urologist with the University of Rochester Medical Center, says scientists used to believe it was because smoking was at one time, more common in men. However, as the rate of smoking increased among women, the proportion of bladder cancers didn’t change.

Investigators have found hormones may play a role in the risk for bladder cancer, specifically the male hormone, testosterone. In one study, castrated male mice were much less likely to develop bladder cancer than male mice that were left sexually intact. The castrated mice that did develop bladder cancer were more likely to have a less aggressive form of the disease. In a follow-up, when the researchers gave androgen-blocking chemicals to the non-castrated mice with bladder cancer, the rate of tumor growth slowed.

Messing says animal study results don’t always produce the same results in humans. However, he hopes to soon start a human trial to study the effects of hormone-blocking therapy.

There is a complication factor in bladder cancer studies. Although the cancer is less common in females, when women do get the disease, they are much more likely to die from it. In fact, Messing says women are 80 percent more likely to die from bladder cancer than men. No one knows why this occurs. One possible reason is that the main sign of bladder cancer, blood in the urine, may easily be mistaken for menstrual flow in a woman. Thus, women may not be diagnosed in early stages of the disease.

SOURCES
Edward Messing, M.D., F.A.C.S. (featured in story), Urologist, University of Rochester Medical Center, c/o: University Public Relations, Box 643, Rochester, NY 14642.

AUDIENCE INQUIRY
For general information on bladder cancer:
American Cancer Society, http://www.cancer.org
American Urological Association, http://www.urologyhealth.org
National Cancer Institute, http://www.cancer.gov