Casán made her theatre debut in 1971 as a model in the show Nerón Vuelve in the theater El Nacional, and later became one of the country's leading vedettes during Argentina's Golden Age of revue.

Her sex symbol status was further cemented during the late 1970s and 1980s, as she starred in various sexual comedy films alongside Alberto Olmedo, Jorge Porcel and Susana Giménez.

Her insult comedy and off-color humor, popularized through her usual feuds with other media personalities, has generated various phrases that are now part of the national lexicon — the press has nicknamed her "karateka tongue".

[1] In 2013, the Buenos Aires Herald wrote that "[her] larger than life persona is a pop icon as much for her stage performances as for her bold, daring public statements.

She worked with outstanding revue actors during the 1970s, such as Nélida Lobato, Adolfo Stray, Don Pelele, Pablo Barbieri, Juan Verdaguer, and José Marrone.

Casán ran a much-publicized, though unsuccessful, 2005 campaign for a seat in the lower house of Argentina's National Congress, the Chamber of Deputies, on the Movimiento Federal de Centro, a new center-right party she created.

Remaining active in the theatre, in 2009 she performed in Une visite inopportune, by local playwright Copi, and directed by the French dramatist Stéphan Druet.