Venezuela President Hugo Chavez announced he was returning to Cuba Saturday for additional radiation treatment after his latest cancer surgery. Chavez said in a message broadcast on radio and television that \"I will leave tonight for Havana to start radiation therapy tomorrow.\" The news came ahead of his bid for re-election later this year. Chavez underwent surgery in Havana on February 26 to remove a cancerous tumor around the pelvis, the same area from where a first tumor was extracted in June 2011. Officials in Caracas have never specified what type of cancer the president is suffering from, but they have denied the disease has spread to other organs. Latin America\'s highest-profile leftist leader, who has been in power since 1999, faces a strong challenge in the October 7 presidential election from 39-year-old Henrique Capriles, the candidate of a unified opposition.