The 49-year-old, who was a regular as barmaid Raquel in the ITV soap until 1996, appeared in The Last Tango In Halifax.
Lancashire, who plays police sergeant in new BBC1 drama Happy Valley, told Radio Times: "Soaps are a double-edged sword. There can be prejudice from some writers and producers who feel you will lower the currency of their work if you've been in one. You have to rise above such ludicrous prejudice.
"Sometimes it's necessary for soaps to hang on to an audience by sensationalising, but it's a beast I don't understand any more, an art form that has fostered extraordinary talent. It's a great arena to learn your craft before you move on.
"We're all actors and work across an enormous amount of media, radio, television, or standing outside a supermarket in a Weetabix outfit."