Michael Douglas spoke about his throat cancer battle for the first time in public last night on David Letterman's Late. But talking on the chat show, he revealed that he had already started his treatment and that his odds of recovery were high. However, he added, 'It hurts, it comes and goes in waves. It knocks you out really hard.' Douglas, 65, said he faced an 'eight-week struggle' to cope with his treatment for stage four throat cancer, which the actor said had been caused by his smoking and drinking. Drawing gasps from the audience, shocked at the severity of the diagnosis, Douglas added that he didn't expect to go under the knife, however. He said: "I've got cancer. I found out about three weeks ago. It's throat [cancer]." 'This particular type of cancer is caused by alcohol and drinking. I smoked cigarettes and drank.'