Douglas optimistic about beating cancer

>>> first let's begin with michael douglas and his fight against throat cancer . last night he shocked late-night tv viewers by admitting that the cancer that he is now fighting is stage 4. but douglas is confident he can beat it.

>> reporter: michael douglas looked a bit thinner than the stoic actor we have come to know, but was upbeat on the show with david letterman . just weeks ago, douglas learned of his diagnosis, throat cancer .

>> i finished my first week of radiation and chemo.

>> you have never looked better to me, this proves that you're a tough guy.

>> the tone on the late show was light.

>> i found out about it three weeks ago. i said, gee, just when i found out i was going to be on your show.

>> reporter: but the subject matter was serious.

>> you don't sound like you have throat cancer . why is that?

>> because i'm on stage.

>> reporter: douglas says his cancer was caused by years of smoking and drinking, but he likes his odds, he says there's a big chance for a full recovery. married to katharine zeta jones , he has had one of the most storied careers in history. his son cameron was sentenced to five years on drug charges.

>> i once said greed is good. why don't you start calling me gordon.

>> reporter: and just as his " wall street " sequel hits the big screen , his wife is suing him for 50% of his earnings from the movie.

>> this is nbc "nightly news" with brian williams .

>> reporter: he's suffering from a cancer that could cripple one of his trademarks that makes him so recognizable.

>> this is the first week of the chemo and the radiation, the radiation continues to burn your mouth.

>> did they find it early enough for your liking?

>> i certainly hope so.

>> i feel like i want to do something for you. can i do something for you?

>> give me a hug.

>> all right, by god.

>> reporter: letterman gave him a hug, the audience gave him a standing oaf yags. ovation.

>> as we said before, we're