Sen. John McCain, recently diagnosed with an aggressive form of brain cancer, is returning to Arizona to begin radiation and chemotherapy.



In a statement Friday, his office said he will undergo further treatment at the Mayo Clinic in Phoenix while maintaining his work schedule. The senator, who won a sixth term last year, plans to return to Washington at the end of Congress' August recess.



The 80-year-old McCain had a blood clot removed about his left eye earlier this month and was diagnosed with glioblastoma, an aggressive type of brain cancer.



He returned to the Senate on Tuesday, casting a crucial vote to move ahead on health care legislation. Early Friday morning, he dashed GOP hopes on legislation by opposing a repeal measure.