Touted as the Boy Soprano, the Toronto-born Breen starred in seven b musicals for RKO from 1936 to 1939, entertaining Depression-era audiences.

In 1942, the then 15 year old was embarassed after hearing his Mickey Mouse-like speaking voice in Johnny Doughboy and quit the movie business. He tried to revitalize his career with a nightclub act. It was moderately successful and got him several TV guest shots into the early '60s.

He then hosted a local TV show in New York City and was briefly signed to Motown Records in 1964 (his album was unreleased).