Based on more than 25,000 men who had prostate surgery, the study also found that rates of subsequent surgery for urinary incontinence doubled between five and 15 years after the first operation.

"The risk of incontinence will continue and (will) increase from a cancer survivor's perspective," said lead author Dr. Robert Nam, from the University of Toronto.

The study, published in the Journal of Urology, is the first to suggest that urinary incontinence may be a long-term problem for men many years after their prostate surgery, according to the researchers.

"Doctors should discuss with patients the risk of needing incontinence surgery after radical prostatectomy," said Nam, adding that physicians themselves need to be more aware that bladder issues can persist even 15 years after prostate surgery.

An estimated 241,000 new cases of prostate cancer will be diagnosed in the United States in 2012 and the disease will kill about 28,000 men, according to the American Cancer Society.

One of the main side effects of prostatectomy - surgery to remove the prostate gland - is incontinence. Urinary problems usually result from damage to certain nerves and muscles during the procedure.

According to the Prostate Cancer Foundation, about a quarter of men report frequent leakage or no bladder control and the need to use absorbent pads at six months after prostatectomy. But by three years, fewer than 10 percent report using pads at all.

However, the new study's finding that the long-term likelihood of having a surgical procedure to treat incontinence went up with the passage of time suggests that bladder issues persist.

Nam and his colleagues tracked hospital and cancer registry data for 25,346 men who underwent radical prostatectomy between 1993 and 2006.

Overall, nearly five percent of these men had follow-up operations for bladder issues.

And the number of men getting incontinence surgery almost doubled over time, from 2.6 percent at five years post- prostate surgery to 4.8 percent after 15 years.

If the prostatectomy was done after age 60, a man's risk of needing a subsequent surgery for incontinence doubled, Nam's team found.

Among the 15 percent of study subjects who needed radiation treatment after prostate removal, chances of needing incontinence surgery were 50 percent greater than those who didn't get radiation.

The experience level of the surgeon who performed the original prostatectomy also influenced a man's chances of needing bladder surgery.

Men whose surgeons did more than 48 prostatectomies a year were half as likely to need incontinence surgery than men whose surgeons did a lower volume of prostate removals.

The more surgeries a doctor does, "the better the outcome in terms of patients staying dry," said Nam.

The finding further confirms the need for patients to choose surgeons and medical centers with deep experience in treating prostate cancer, said Dr. Peter Scardino, a prostate cancer surgeon at Memorial Sloan-Kettering Cancer Center in New York, who was not involved in the study.

"It suggests the risks of having surgery are higher perhaps than is commonly thought or understood," Scardino told Reuters Health.

The results may also support a recent U.S. government task force guidance stating that routine screening for prostate cancer with blood tests may cause more harm than good.

At the same time, the United States Preventive Services Task Force "went too far" in recommending that prostate-specific antigen (PSA) tests are not needed regardless of age, Scardino cautioned.

"The danger is men will come in and find they have very advanced prostate cancer" because they didn't get tested early enough, he explained.

Men should get tested, he added, but should consider treatment options with caution and better understanding of the risks - such as incontinence.

The problem can be embarrassing as well as expensive for patients.

"There are huge costs associated with dealing with incontinence after radical prostatectomy," Nam told Reuters Health in an email.

These include the cost of daily pads or "adult diapers," drug therapy and, if needed, major surgery performed under general anesthesia to insert a prosthetic device, he explained. In one type of operation, the implant alone costs 8,000 Canadian dollars.

The new study was funded by a grant from the Ontario government, but one author declared a financial interest in several companies that make incontinence drugs.

"It's a tricky decision" whether or not to have a prostatectomy, but men now have an actual measure of incontinence risk from research based upon a large population group, Scardino noted.

"That is the power of the study," he said.

SOURCE: bit.ly/Ny3yR1 Journal of Urology, online June 15, 2012.

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