FRIDAY, May 9 (HealthDay News) -- Clinical practice may be trumping science when it comes to treatments for prostate cancer.

According to a new study, many patients are getting a newer, minimally invasive surgery, because they think it is better than conventional surgery, even though there is little data on actual differences in outcomes between the two.

"Patients are choosing and/or being directed towards treatments without fully understanding how much experience there is with the treatment in general, how much experience their particular physician might have doing a particular treatment, and how that compares to other options out there," said Dr. Ronald D. Ennis, director of radiation oncology at St. Luke's Roosevelt Hospital, Continuum Cancer Centers of New York.

The study, appearing in the May 10 issue of the Journal of Clinical Oncology, found that minimally invasive radical prostatectomy (MIRP) tended to involve fewer complications and shorter hospital stays but a higher risk of needing additional treatment and of experiencing incontinence.

The risks, however, tended to decrease the more experience a surgeon had under his or her belt.

"This reaffirms what many other manuscripts have shown, if you go to an individual who has experience, who does this on a consistent basis, your outcomes will be better," said Dr. Ihor S. Sawczuk, chief of urologic oncology for the Cancer Center at Hackensack University Medical Center, in New Jersey. "If you go to someone who does 20 to 50 procedures a year, that's better than somebody who only does two to three a year."

Men diagnosed with prostate cancer, the second leading cancer killer in males, are presented with a maze of treatment options.

Radical prostatectomy, which is surgery to remove the prostate and some surrounding tissue, is currently the most common treatment in the United States. Men can choose between a minimally invasive procedure (introduced in 2000, which includes both robotic surgery and conventional laparoscopic surgery) or traditional surgery, which, these days, still involves only a small incision.

Surprisingly, use of MIRP, still a new procedure, nearly tripled during the time this study was conducted, from 12.2 percent of procedures in 2003 to 31.4 percent in 2005. This happened despite scant evidence on how MIRP compared with more traditional surgery, the investigators stated.

The reason for this quick adoption, said study author Dr. Jim Hu, director of minimally invasive urologic oncology at Brigham and Women's Hospital/Dana-Farber Cancer Institute in Boston, is heavy direct-to-consumer advertising. "A lot of people are jumping the gun before any studies are out," he said. "And the studies that are out are from high-volume, single-center hospitals or academic institutions rather than what's going on nationwide."

This study involved 2,702 men undergoing one or the other procedure between 2003 and 2005, all of them Medicare beneficiaries.

MIRP was associated with fewer perioperative complications than open radical prostatectomy (29.8 percent versus 36.4 percent, respectively) and shorter hospital stays (1.4 versus 4.4 days).

This was noteworthy, the authors stated, because a greater proportion of older men and those with other health problems chose minimally invasive surgery over open radical prostatectomy. These men would automatically be at higher risk for complications.

But, 27.8 percent of men undergoing MIRP needed salvage therapy (hormone therapy or external-beam radiotherapy) within six months of the surgery, compared with only 9.1 percent of those undergoing the more traditional surgery.

And this procedure was associated with a higher risk of scar tissue, which can lead to incontinence and the need for further surgery.

The study did not look at staging and scoring of the tumor, meaning that some of the differences seen might be due to differences in disease rather than in surgical quality, Sawczuk said.

On the other hand, outcomes between the two procedures were more equal when MIRP was performed by surgeons with greater experience. But studies have shown that surgeons may need to perform as many as 150 procedures to duplicate the results of open surgery and as many as 300 to feel comfortable, Hu said.

"This is relatively new, and patients are all excited about it and, as a result of increased demand, the suppliers or surgeons want to rush and give patients what they want, but this is definitely something where a lot of practice is needed," Hu said.

More information

Visit the National Cancer Institute for more on treatment for prostate cancer.