CHICAGO (Reuters) – Chicago's Roman Catholic Cardinal Francis George had cancerous cells removed from his kidney and liver this week, six years after he underwent surgery for bladder cancer, the diocese said on Friday. George, who oversees 2.3 million Catholics in the nation's third-largest diocese after Los Angeles and New York, had a procedure on Wednesday removing the cancerous cells in his kidney and a nodule on his liver. He discussed a course of treatment with his doctors, the archdiocese said in a brief statement on its website. George, a former president of the U.S. …