Credit: Jason Merritt/Getty Images.

Ryan O'Neal's cancer prognosis is less serious than originally thought.

"Recently I was diagnosed with stage two prostate cancer," he said in a statement to ABC News' "Nightline" today. "Although I was shocked and stunned by the news, I feel fortunate that it was detected early and according to my extraordinary team of doctors the prognosis is positive for a full recovery.  I am deeply grateful for the support of my friends and family during this time, and I urge everyone to get regular check-ups, as early detection is the best defense against this horrible disease that has afflicted so many."

People magazine previously said that O'Neal, 70, had been diagnosed with stage four prostate cancer.