Smoking linked to half of all bladder cancers
November 9, 2010 - 10:00 pm
By KRISTI EATON
VIEW ON HEALTH
When most people think of smoking-related cancers, they probably think lung cancer. Some people may also think about throat cancer. Few people, however, realize that smoking is the primary risk factor for bladder cancer, the sixth most common cancer in the United States.
Bladder cancer is cancer of the cells that line the bladder, which holds the body's urine. Like other cancers, bladder cancer is a cell abnormality.
"All cancer happens when normal cellular machinery lose the normal mechanisms that control cell division. It's a genetic failure," says Dr. Brian Golden, a urologist at Urology Institute of Nevada. The cancer grows in the wall lining of the bladder and can spread deeper and deeper into the tissue and surrounding organs. The National Cancer Institute estimates than more than 70,000 new cases of bladder cancer are diagnosed each year, and 14,680 deaths will be attributed to the disease in 2010.
It is largely an environmental disease, Golden says. In the United States, it is mainly caused by smoking. In other countries, like Egypt, parasites may play a role in the cancer's development and growth. "But here," he adds, "it's smoking that causes at least half of all bladder cancers."
When somebody inhales combusted tobacco, he explains, random poisonous compounds are absorbed through the person's lungs, stomach and gut, and travel through the bloodstream, eventually reaching every corner of the body -- heart, kidneys, down to the ureters and to the bladder.
"All along the way, the poisons have been in contact with structures inside the person," Golden says.
The poisons sit in the bladder for hours before being forced out in the urine, he adds.
Golden says many times his patients are surprised and angry when they find out smoking can cause bladder cancer.
"People are like, 'I know it (smoking) causes lung cancer, but I had no idea it causes bladder cancer.'" the doctor says. "Most people are surprised when I tell them their bladder cancer is caused by 30 years of smoking a pack a day. Some of them are angry when I tell them that because they say nobody ever told them that."
Dr. Victor Gregoriev from Mountain View Hospital has similar experiences with patients.
"I think people get surprised that there is more of a connection between smoking and bladder cancer than there is smoking and lung cancer," he says.
Although smoking is the leading cause of bladder cancer here in the United States, people who have not smoked a single cigarette in their life can still be susceptible to the disease due to other causes. Certain types of dyes found in hair dye have been tied to bladder cancer, says Dr. Oscar Goodman, an assistant faculty member at the Nevada Cancer Institute. Another leading causeof bladder cancer, particularly in Nevada, is arsenic, a naturally occurring element with no taste and no smell.
"That's important because here in Las Vegas, we get most of our drinking water from mountain run off and that's how arsenic actually accumulates in the water supply," he explains.
In Las Vegas, bladder cancer is more common and appears to be more lethal, based on observational studies, says Goodman, who is also an assistant professor at University Medical Center in the Department of Internal Medicine. "It's a major health problem here in Nevada for sure."
Although it can be lethal and aggressive, there are usually few symptoms of the cancer, Golden says. The most common way it presents itself is through blood in the urine, usually detected through a urinalysis because the quantity is so small.
"That should generally be a warning sign. Generally, if you see that in urine, you should get additional testing," he says, adding that patients are usually referred to a urologist who will make the diagnoses. "The only way to really diagnose it is to put a camera up into the bladder and do a biopsy."
He says occasionally, people will have back pain or urinate bits of tissue.
Men are far more likely than women to develop the cancer. Of the 70,000 new cases expected each year, 52,000 are estimated to be in men. And of the approximately 14,000 deaths each year, 10,000 are men. Caucasians have a greater risk of getting the cancer, according to the Mayo Clinic, and the older you get, the more likely you are to get it. Although it appears in people of all ages, it's rarely found in individuals under 40.
Studies have shown that previous treatment with the anti-cancer drug cyclophosphamide (brand name Cytoxan) as well as radiation treatments targeted at the pelvis for previous cancer can increase a person's chances of being diagnosed with bladder cancer. The treatment and prognosis for bladder cancer patients varies widely based on the grade and stage of the cancer. The grade of the cancer, according to Golden, is determined by how the cancer cells look under a microscope.
"A higher grade cancer looks more abnormal," the doctor explains. Low grade cancer, on the other hand, looks almost normal, just with an abnormal number of cells or layers.
The stage of cancer is based on where it has spread. If it low stage, it has remained confined within the inner layer of the bladder, Golden says. As it invades to deeper layers, the stage becomes higher. Golden says people with low grade, low stage bladder cancer have a low risk of fatality, but also have a higher chance of recurrence.
If the cancer is confined to the cells that line the bladder, Goodman says more than 90 percent of patients will be cured by removing the tumor.
But the rate drops dramatically as the depth of the tumor increases. At that point, the standard practice is to remove the bladder and create a new way of eliminating urine from the body using the small intestine, Golden says.
Many bladder cancer patients whose bladders must be removed undergo a procedure called urostomy, in which surgeons create an opening called a stoma to allow urine to collect in a bag outside the patient's body.
A Las Vegas man has developed a system for making this bag more comfortable and convenient to use while sleeping. Dick Rogers, a bladder cancer and urostomy patient himself, developed the Night Pouch System, which makes it easy to suspend the bag at the bedside in pouch that guards against overflow and leakage of the urostomy bag.
Golden says people should check their urine analysis occasionally with their primary care physician. In addition, he adds, it is important to stay hydrated, as people with chronic urinary infections have a greater chance of developing bladder cancer.