Mitt Romney. (Jabin Botsford/The Washington Post)

Mitt Romney, the 2012 Republican presidential nominee who is preparing for a possible Senate campaign in Utah, was treated for prostate cancer last summer, two people close to Romney said Monday.

“Last year, Governor Mitt Romney was diagnosed with slow-growing prostate cancer,” a Romney aide said in a statement. “The cancer was removed surgically and found not to have spread beyond the prostate.”

Romney's prognosis was described by a second person close to the former Massachusetts governor as “very good” and he was “treated successfully.” Both of the people spoke only on the condition of anonymity because of the sensitivity of the matter.

“Mitt Romney was treated over the summer for prostate cancer,” the second person said. “He was treated surgically by Dr. Thomas Ahlering at UC Irvine Hospital in California. His prognosis is very good. He was treated successfully.”

Romney, 70, is in good heath and went skiing with family in recent days, the person said. Although he has not announced his future political plans, Romney is widely expected to mount a run for the Senate seat being vacated at the end of this year by the retiring Sen. Orrin Hatch (R-Utah).

During his 2012 presidential campaign, Romney released a letter about his health from his longtime personal physician, Randall D. Gaz at Massachusetts General Hospital, who described the then-candidate as a “healthy appearing, energetic, strong, physically fit male.”

Gaz wrote that Romney had a mild enlargement of the prostate and that his family has a history of prostate cancer.