Douglas discussed how the support from friends, family -- and his fans -- helped his recovery a great deal and how he didn't hide anything from his children, Dillon, 10, and Carys, 7.
"I told them about the cancer, you know, right from the beginning, because I was going to be an in-and-out patient," Douglas said. "But I told them it was hopeful. And I also took them down to a couple of radiation treatments. So they came into the room and they saw all the 'Star Wars' treatment going around."
The "Wall Street" actor said he knows now he is in his "third act," saying the cancer has "put a timeline on my life. I'm 66 now. You know, I'm fortunate... It's definitely a third act. And so you're a little more conscious of your time and how you choose to spend it."
The sit-down will air in two parts, with the first interview airing Tuesday on "Today," and the second set for the Jan. 23 edition of "Dateline NBC."