"As soon as I found out I had the breast cancer gene, I thought: 'The odds are not in my favor,' " The Talk co-host, who recently turned 60, tells the U.K.'s Hello! magazine, adding that she didn't want to live under the cloud of cancer.
"I decided to just take everything off," she reasoned. Osbourne underwent the 13-hour operation last summer, a family rep confirms to PEOPLE.
In the interview, Osbourne says her recent health problems began with a leaking breast implant.
"It's not 'pity me,' " says Sharon, calling hers "a decision I made that's got rid of this weight that I was carrying around."