Longtime MSNBC host and Philadelphian Chris Matthews has been notably absent from Hardball for over a week. On Monday night, viewers found out why — the fiery host is recovering from surgery after a recent cancer diagnosis.

“Chris is recovering from prostate cancer surgery last week,” fill-in host Steve Kornacki told viewers at the end of Monday night’s show. “The procedure went well, but he’s taking a few days to get back into fighting shape.”

Matthews, 73, last hosted Hardball on Oct. 4. MSNBC declined further comment about his cancer diagnosis, and it’s unclear when the longtime host could return to the network.

Matthews has been the outspoken host of Hardball for the past 25 years, which began in 1994 on NBC’s now-defunct America’s Talking channel. He began his career as a political aide on Capitol Hill for several Democratic congressmen, including a six-year stint as chief of staff to longtime Speaker of the House of Tip O’Neill. Matthews also worked as the Washington, D.C., bureau chief for the San Francisco Examiner and as a columnist for the San Francisco Chronicle.

Despite flirting with the idea several times, Matthews has only run for political office once in his life. Back in 1974, he lost to former Rep. Joshua Eilberg in the Democratic primary for Pennsylvania’s fourth congressional district, which includes most of Montgomery County and a small part of Berks County.

Matthews told the Inquirer back in 2014 that it was his grandfather that spurred his lifelong interest in politics.

“My grandpa Charles Shields was a ward leader in Nicetown. We talked politics all the time. Every day, he walked five miles down to Tioga to buy the first edition of The Inquirer,” Matthews said.