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Venezuela's President Hugo Chavez gestures as he attends an event event honoring him at the Teresa Carreno theater in Caracas, Venezuela, Thursday, Feb. 23, 2012. Chavez is headed to Cuba Friday for surgery to remove a potentially cancerous tumor while the nation's congress on Thursday unanimously approved permission for Chavez to leave, a formality required by the nation's constitution. (AP Photo/Fernando Llano)

Venezuela's President Hugo Chavez gestures as he attends an event event honoring him at the Teresa Carreno theater in Caracas, Venezuela, Thursday, Feb. 23, 2012. Chavez is headed to Cuba Friday for surgery to remove a potentially cancerous tumor while the nation's congress on Thursday unanimously approved permission for Chavez to leave, a formality required by the nation's constitution. (AP Photo/Fernando Llano)

Hugo Chavez's weeklong silence spurs uncertainty

Venezuelan President Hugo Chavez has been out of sight for a week, speaking only through Twitter messages and written statements while undergoing cancer treatment in Cuba.