"Incurable is a tough word," the Mary Tyler Moore Show star, 73, acknowledges.
Still, she plans to go out fighting and smiling.
"I’m not dying until I do," says the sitcom legend.
One part of the interview did bring the actress to tears. That's when she spoke of her devoted longtime husband Tony Cacciotti.
You can watch a sneak peek of the interview here. Guthrie's entire interview will air on Monday’s TODAY show.