President Hugo Chavez announced Friday in a Twitter message that he was heading home to Venezuela after three weeks in Cuba where he underwent cancer surgery. \"Good afternoon, good world! Right now we are departing from the Jose Marti International Airport [in Havana] Heading South, Heading to the Great Motherland! Thank You My God!\" read Chavez\'s message. Chavez underwent surgery in Havana on February 26 to remove a cancerous tumor around the pelvis, the same area 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. In a second tweet, Chavez wrote that he had lunch with his ally and friend Fidel Castro, the aging former Cuban leader, and that Cuban President Raul Castro bid him farewell at the airport. Chavez, 57, said he would need a round of cancer radiotherapy to treat his condition, but insists he feels optimistic about his prospects. 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.