There is a "very strange" bout of cancer affecting several South American leaders, and the U.S. may be responsible, at least according to Hugo Chávez. The Venezuelan president believes that his least favorite government to the north is using cancer as a political weapon. "It's very difficult to explain, even with the law of probabilities, what has been happening to some of us in Latin America," he said in a speech to the military. "Would it be so strange that they've invented technology to spread cancer and we won't know about it for 50 years?" Brazilian President Dilma Rousseff and her predecessor, Luiz Inácio Lula da Silva, as well as Paraguay's Fernando Lugo and, most recently, Argentine President Cristina Fernández de Kirchner have all been diagnosed with cancer. Chávez himself has an undisclosed type of cancer and has called for a regional summit of his fellow leaders who are currently suffering from or have battled cancer.