Doctor Who actress Elisabeth Sladen has died following a battle with cancer. She was 63.The Liverpool-born star, who played the Doctor's assistant Sarah Jane Smith since the Seventies, passed away yesterday morning after suffering from the illness for some time.The BBC confirmed her death in a statement: 'It is with much sadness that we can announce Elisabeth Sladen, the much-loved actress best known for her role as Sarah Jane Smith in Doctor Who and CBBC's The Sarah Jane Adventures, passed away this morning. She was 63.'