Jennings announces lung cancer diagnosis

ABC's "World News Tonight" anchor Peter Jennings was diagnosed with lung cancer Monday and will continue working when possible during his treatment, he said in an e-mail to co-workers.

Jennings, 66, will begin chemotherapy next week, ABC News spokeswoman Cathie Levine said. ABC News anchors Charles Gibson, Elizabeth Vargas and others will fill in for Jennings when he can't work, ABC News President David Westin said.

"There will be good days and bad, which means that on some days I may be cranky and on some days really cranky," Jennings, a former smoker, wrote in the e-mail. Jennings quit smoking "a number of years ago," Levine said.

Top news anchors at U.S. broadcast networks have departed since December, with CBS's Dan Rather, 73, and NBC's Tom Brokaw, 65, stepping down. ABC last week said Ted Koppel, 65, the anchor of its late-night news magazine "Nightline," would leave the program when his contract expires in December. Jennings has anchored "World News Tonight" since 1983.

Jennings, who has won 14 Emmys, joined ABC News in 1964, anchoring the evening news from 1965 to 1968.