The Mayo Clinic discovered last summer that Brokaw has multiple myeloma, a cancer affecting blood cells in the bone marrow, NBC News said. His doctors are optimistic about his treatment and encouraged by his progress since the August diagnosis, the network division said.
In a statement released by NBC, Brokaw said he remains, in his words, "the luckiest guy I know."
"With the exceptional support of my family, medical team and friends, I am very optimistic about the future and look forward to continuing my life, my work and adventures still to come," he said.
The former national anchor, now an NBC News special correspondent, has continued to work on projects during his treatment and is contributing to NBC Sports coverage of the Winter Olympics, NBC said.
Brokaw, who turned 72 on Feb. 6, said he is grateful for the interest in his health but wants to keep it a private matter.
He began his career with NBC News in its Los Angeles bureau in 1966, later serving as its White House correspondent during the Watergate scandal before becoming anchor of "NBC Nightly News" in 1983.
Brian Williams replaced him as anchor in 2004.
Brokaw is the author of several books including "The Greatest Generation," his celebration of Americans who endured the Great Depression and World War II.