NBC's Tom Brokaw announced tonight that he's been secretly battling multiple myeloma, a cancer that affects bone marrow, since his diagnosis last August.

Brokaw says that he and his physicians are very encouraged with the progress he's making adding, "I remain the luckiest guy I know."

Brokaw said he doesn't want to continue to comment publicly on his diagnosis, saying, "I am very grateful for the interest in my condition but I also hope everyone understands I wish to keep this a private matter."

[image via AP]