[“Dennis Hopper 1971” by ANDY WARHOL] ASSOCIATED PRESS: Dennis Hopper has been diagnosed with prostate cancer and is canceling all travel plans to focus on treatment, his manager said Thursday. The 73-year-old actor and artist is being treated through a “special program” at the University of Southern California, said Sam Maydew. Asked about Hopper’s prognosis, Maydew said, “We’re hoping for the best.” He would not elaborate on the actor’s condition. MORE RELATED: Q&A With Dean Wareham [Video: Dean and Britta @ Prospect Park: Dennis Hopper Screen Test]