Studies presented this past weekend may help men weigh the risks and benefits of different types of prostate surgery.

Prostate cancer patients who opt for surgery instead of radiation or radioactive "seeds" have a range of options.

Traditional prostate surgery — in which doctors wield instruments by hand — has the longest track record for keeping men cancer-free and remains the "gold standard," says Martin Sanda, director of the prostate care center at Boston's Beth Israel Deaconess Medical Center. But a growing number of men are attracted to two newer types of surgery that have been performed in the U.S. for only about six years, Sanda says.

Laparoscopic operations allow doctors to make several tiny, "keyhole" incisions, while robotic procedures let surgeons operate with the help of mechanical arms. The newer procedures cause less blood loss than traditional techniques, in which doctors must make incisions big enough to fit their hands, Sanda says.

In a study of 575 men presented Saturday at a meeting of the American Urological Association in Anaheim, Calif., doctors at Eastern Virginia Medical School in Norfolk found little difference in quality of life after any of the three surgeries. After 18 months, about 75 percent of men had the same urinary control as before surgery; 40 percent regained the same level of sexual function.

In a five-year, multihospital study of 602 men presented Sunday, Sanda found that the newer procedures may be as good as the older surgeries in many ways, especially as doctors get more practice.

Men treated with the newer surgeries had less scarring and pain, the study shows. They recovered control over urination as well as patients who opted for the older procedure. In the first year, however, men who opted for traditional surgery had better sexual function. For men treated in the third year of the study — after surgeons had performed more of the new procedures — sexual function was equally good, no matter which technique men chose, Sanda says.

That suggests that surgeons face a substantial "learning curve" when tackling complex procedures, he says. In the year before the study, surgeons had performed an average of 79 traditional prostate removals, but only 15 laparoscopic.

Indeed, one of the country's most experienced prostate surgeons, Joseph Smith of Vanderbilt University Medical Center, wrote in a 2005 paper that it took him 150 robotic surgeries to achieve the same results as in traditional prostate removal. Smith, who has performed more than 2,500 traditional prostate surgeries and 1,500 robotic ones, says he now uses a robot for about 90 percent of his procedures.

Experts say men must grapple with many unanswered questions when selecting prostate surgery.

Peter Scardino, chairman of surgery at New York's Memorial Sloan-Kettering Cancer Center, notes that doctors don't yet know which technique best cures cancer. The new procedures haven't been around long enough, says Scardino, who was not involved with the new studies.

Sanda notes that he plans to follow the men in his study for 10 years to learn whether one type of surgery prevents relapses better than others.

Men lack another key piece of data, Scardino says: No one has conducted a randomized controlled trial — a type of study considered to be definitive — of all three methods. Such a trial would be daunting, largely because few men would agree to be randomly assigned to a type of surgery, he says. And Scardino says many of the articles that have been published present overly sunny pictures of the new procedures. Hospitals are much more likely to trumpet their successes with robots than to admit disappointing results in print.

"I tell patients it's the surgeon that matters, not the tool," Scardino says.