Blade Runner is also a 1979 novel/screenplay by William S. Burroughs, completely unrelated in plot to the Ridley Scott movie, though it is also set in a dystopian future. The Burroughs novel is about a future of rampant plague where doctors are virtually outlawed and heroic teenagers called "blade runners" smuggle them their medical supplies under the nose of an authoritarian government.
"Do Androids Dream of Electric Sheep?" never uses the phrase "blade runner" - Ridley Scott purchased the rights to the name from Burroughs for the movie. It's not hard to see why Scott didn't want to retain the rather cumbersome title of the novella for the movie, particulary given that Deckard's artificial sheep, which figures prominently in the novella, never made it into the movie.