Tom Brokaw revealed Tuesday that he is fighting cancer.

The 74-year-old former "NBC Nightly News" anchor revealed on the network's blog that he was diagnosed with multiple myeloma, a cancer affecting blood cells in the bone marrow, in August. Although Brokaw said he was keeping details about his disease private among his family, he said the prognosis is positive.

"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 in a statement.

Brokaw joined the network in 1966 and has worked on several news programs, including the "Today" show and "Dateline NBC."

He continued to contribute to the network's news broadcasts following his retirement from the "Nightly News" anchor desk in 2004 and currently is contributing to NBC's Olympics coverage.