"I am lucky," Kerry said. "I'm going to be cured."
Kerry, 59, the junior senator from Massachusetts and a decorated Vietnam War veteran, said he was diagnosed with an early stage of cancer and would soon return to work. "I don't think it's going to have any impact at all" on his campaign, Kerry said.
Dr. Patrick Walsh, urology chief at The Johns Hopkins Hospital who pioneered a safer form of prostate removal, will perform the surgery Wednesday morning.
Walsh said Kerry has "a very early, curable" form of cancer, and should be back at work in a couple of weeks.
Kerry, who is otherwise fit, has a 95 percent rate of being cured, Walsh said, citing his own newly published study of 2,000 patients who have undergone surgery.
The surgery complicates Kerry's campaign to win the Democratic presidential nomination but, with the first voting still 11 months away, aides characterized the diagnosis as a minor setback.
Kerry, whose father died of prostate cancer while he was in his 80s, was diagnosed at a fairly young age. Walsh said that helps his chances of recovery.
"Sen. Kerry is a poster boy for early detection," said Walsh. "He's a very active 59 year-old in overall great health who took to heart the advice we give to all men his age and insisted on regular check-ups. We caught this very early and for that reason the prognosis couldn't be more optimistic."
About 220,000 men will be diagnosed with prostate cancer this year, and 28,900 will die, the American Cancer Society estimates. It is the second-leading cancer killer of men. But caught early, it is highly curable.
Surgery is the most common treatment for prostate cancer that has not yet spread beyond the doughnut-shaped gland that surrounds the urethra.
Men over 50 are routinely screened for prostate abnormalities with a blood test for the prostate specific antigen, or PSA.
Kerry has made strides against his five rivals in a Democratic field that could grow in the next several weeks. Sen. Bob Graham, D-Fla., who may enter the race after recovering from heart surgery, called Kerry to wish him well.
Sen. John Edwards of North Carolina and Rep. Richard Gephardt of Missouri also telephoned Kerry before the news conference. Former Vermont Gov. Howard Dean, the only doctor in the race, said in a statement, "I have every confidence that he'll come through this well."