Giuliani's political future cloudy after prostate cancer diagnosis.

Byline: Lisa Anderson

NEW YORK _ Clouding what had been shaping up as the nation's most watched U.S. Senate race, Mayor Rudolph Giuliani on Thursday disclosed he has prostate cancer and said a decision to run against Hillary Rodham Clinton will come only after doctors determine a course of treatment.

Appearing cheerful and smiling, Giuliani said at a news conference that he hoped to continue his Senate bid, but after treatment for what he described as "an early stage" of "a treatable form" of the cancer.

"I hope that I'd be able to run, but the choice that I'm going to make is going to be based on the treatment that's going to give me the best chance to have a complete cure,'' said Giuliani, whose father died of the disease in 1981.

For months, much attention has been focused on the potential of a matchup between two people with a seemingly equal capacity to polarize and inspire _ a prospect made all the more rich because it would take place in the roiling media cauldron of New York.

Guiliani's diagnosis also presents a test of just what impact a serious, but highly treatable, illness in a…