John McCain — a former Vietnam prisoner of war, 6-term U.S. Senator from Arizona and 2008 GOP Presidential nominee who battled an aggressive form of brain cancer in the latter part of his storied career — has died … TMZ has learned According to a statement from McCain’s office, he died Saturday at 4:28 PM, adding … “With the Senator when he passed were his wife Cindy and their family. At his death, he had served the United States of America faithfully for sixty years.”The news comes not long after McCain made the decision to stop medical treatment after a year-long battle with brain cancer. As we reported … McCain’s family said age was a factor in John’s decision to cease treatment. Fact is … he had surpassed expectations for survival.