CHICAGO (Reuters) - Men have the best chance of surviving prostate cancer in the long run if the gland is removed, particularly if they are younger or the cancer is aggressive, a study said on Monday.

The finding came from Dr. Arnaud Merglen and colleagues at Geneva University in Switzerland who studied data from a cancer registry for 844 Swiss men diagnosed with early-stage prostate cancer beginning in 1989 and whose history was traced for a number of years.

Men with prostate cancer generally have a number of options ranging from doing nothing -- so-called "watchful waiting" since the cancer can be slow to develop -- to radiation therapy and removal of the gland. The last choice can lead to incontinence and impotence.

The Geneva study, published in this week's Archives of Internal Medicine, said it was believed to be the first research to compare "the effects of all therapeutic methods used in routine health care practice" for the disease and their specific effect on death from it.

It found that in the short-term, up to five years, there was little difference in survival among men based on the kind of treatment they received.

But after 10 years, "patients treated with radiotherapy or watchful waiting had a significantly increased risk of death from prostate cancer compared with patients who underwent prostatectomy (removal of the gland)," the study said.

The survival rates after 10 years were 83 percent for removal, 75 percent for radiation, 72 percent for watchful waiting, 41 percent for hormone therapy and 71 percent for other treatment.

"There is growing evidence from observational studies that prostatectomy offers the best chance of long-term specific survival in men with localized prostate cancer, in particular younger patients and those with poorly differentiated tumors," the study concluded.