Japan’s former empress Michiko “safely” underwent surgery on Sunday after the 84-year-old was diagnosed with early-stage breast cancer, the Imperial Household Agency said.Michiko’s husband Akihito formally stepped down as emperor in April, the first abdication for 200 years in the world’s oldest monarchy.Her operation began Sunday morning “as scheduled” at the University of Tokyo Hospital, the agency official said.“It ended safely and (she) went back to her room,” the official said, adding that…