Cancer doctor on Jimmy Carter’s condition, treatment

August 21, 2015, 7:13 AM|Former President Jimmy Carter is fighting cancer with grace. He revealed there is melanoma on his brain and went through radiation Thursday. His treatment includes pembrolizumab, a drug approved just last year. Dr. David Agus, who leads the Westside Cancer Center at the University of Southern California, joins “CBS This Morning” to discuss Carter’s prognosis.