NBC's Tom Brokaw has been diagnosed with multiple myeloma, a type of cancer than affects the white blood cells in bone marrow.

The 74-year-old former anchor of "NBC Nightly News" is currently contributing to the network's Winter Olympics coverage in Sochi. He released a statement through the network on Tuesday: "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."

"I remain the luckiest guy I know," Brokaw said, and he offered thanks for everyone's concern but concluded, "I wish to keep this a private matter."

The South Dakota native was diagnosed with the cancer at the Mayo Clinic in August and has continued to work while receiving treatment.

Costas takes leave from Olympics

Bob Costas will be sitting out NBC's prime-time and late-night coverage of the Winter Olympics while he recovers from an infection that has spread to both eyes. "Today" host Matt Lauer will be filling in for Costas, who has been told to rest. In a statement, Costas said: "As a practical matter, I simply couldn't do my job because my eyes had become so blurry, watery and sensitive to light. I'm hopeful the symptoms will improve in the next couple of days and I can return to the broadcast." His eye infection has become the topic of conversation on social media and sports talk radio. Costas' sitting out the Olympics, even for a night, is a major break with Olympic coverage tradition. He has hosted all of NBC's prime-time Olympics coverage since 1988 and has covered every single Olympics since 2000.

'doonesbury' hiatus: Your daily dose of new "Doonesbury" comics is about to go away. Beginning March 3, the daily strip will go on indefinite hiatus as creator Garry Trudeau focuses on his Amazon online comedy "Alpha House." Trudeau will continue to write new "Doonesbury" strips for Sundays, and will curate a selection of historic comics for weekdays. "Alpha House" is a political satire about four GOP senators sharing a house in Washington. It just completed its first season and was renewed. "To my delight, Amazon Studios has recently decided to move forward with another season of 'Alpha House,' " Trudeau said in a statement. "It's a wonderful opportunity, but as I discovered last year, the demands of producing the show are considerable, and my efforts to return to the daily strip while we were still in production had to be abandoned." But the veteran ­cartoonist left the door open for a return.

Bill Ward, news services