Breen, an alumnus of The Second City in Chicago, is known for his role in an HBO sketch comedy series, Not Necessarily the News, from 1983 to 1990.

[1][2] More recently, Breen produced the popular improv comedy series Whose Line Is It Anyway?, as well as The Wayne Brady Show.

[1] In 1975, he visited Chicago to see a friend, actress Miriam Flynn, perform in The Second City comedy troupe.

[2] In 1979, Breen began performing a series of revues at Second City alongside Jim Belushi, Tim Kazurinsky, and George Wendt.

[1][2] Breen died on December 29, 2017, at his home in Los Angeles, California, at the age of 67, following a seven-year battle with cancer.