US presidential candidate John Edwards has said his wife Elizabeth's cancer has returned.
But Mr Edwards said his election campaign would go on. He said both he and his wife were "very optimistic about this".
Elizabeth Edwards, 57, was treated for breast cancer after the 2004 presidential campaign.
A former lawyer and senator who ran with John Kerry in 2004, Mr Edwards declared his candidacy last year.
"The campaign goes on. The campaign goes on strongly," he told reporters at a news conference in North Carolina, his wife by his side.
Mr Edwards said the disease was incurable, but treatable, and that Mrs Edwards would live with the disease for as long as she was alive.
"The bottom line is her cancer is back. We are very optimistic about this because, having been through some struggles together in the past, we know, the key is to keep your head up," he said.
Mrs Edwards said she did not have any symptoms of the disease.
"I don't look sickly, I don't feel sickly. I am as ready as any person can be for that," she said at the news conference.
Mr Edwards cancelled campaign appearances earlier in the week to be with his wife when she had to undergo further tests following a routine medical appointment on Monday.
He said a biopsy had shown his wife had cancer in the bone on a rib on her right-hand side.