Researchers have found long-term evidence that active control of localized prostate cancer is a safe alternative to immediate surgery or radiation.

The results, released Saturday, are encouraging for men who want to avoid treatment-related sexual and incontinence problems, said Dr. Stacy Loeb, a prostate cancer specialist at NYU Langone Health who was not involved in the research.

The study directly compared the three approaches: surgery to remove tumors, radiation treatment, and monitoring. Most prostate cancers grow slowly, so it takes many years to see the results of the disease.

«There was no difference in 15-year prostate cancer mortality between the groups,» Loeb said. And prostate cancer survival for all three groups was high: 97% regardless of treatment approach. “That is also very good news.”

The results were published Saturday in the New England Journal of Medicine and presented at a European Association of Urology conference in Milan, Italy. Britain’s National Institute for Health and Care Research paid for the research.

Men diagnosed with localized prostate cancer should not panic or rush treatment decisions, said lead author Dr. Freddie Hamdy, of the University of Oxford. Instead, they should «carefully consider the potential benefits and harms caused by treatment options.»

A small number of men with high-risk or more advanced disease need urgent treatment, he added.

The researchers followed more than 1,600 UK men who agreed to be randomly assigned to undergo surgery, radiation or active monitoring. The patients’ cancer was confined to the prostate, a walnut-sized gland that is part of the reproductive system. The men in the follow-up group underwent regular blood tests and some underwent surgery or radiation.

Death from prostate cancer occurred in 3.1% of the active follow-up group, 2.2% in the surgery group, and 2.9% in the radiation group, differences considered statistically insignificant.

At 15 years, cancer had spread in 9.4% of the active follow-up group, 4.7% of the surgery group, and 5% of the radiation group. The study began in 1999, and experts said current monitoring practices are better, with MRIs and genetic testing guiding decisions.

“Now we have more ways to help detect that the disease is progressing before it spreads,” Loeb said. In the US, about 60% of low-risk patients choose monitoring, now called active surveillance.

Hamdy said the researchers had seen the difference in cancer spread at 10 years and hoped it would make a difference in survival at 15 years, «but it didn’t.» He said that spread alone does not predict death from prostate cancer.

«This is an exciting new finding, useful for men when making treatment decisions,» he said.