In a video statement released by Kensington Palace, the Princess of Wales announced she has been diagnosed with cancer and is in the "early stages" of chemotherapy treatment. CNN learned that Prince William and Princess Catherine wanted to wait for their three young children to be out of school for Easter break before making the announcement. This comes more than two months after Princess Catherine temporarily stepped away from public events following what the palace said at the time was surgery for a non-cancerous abdominal condition. CNN Royal Historian Kate Williams and British television host Trisha Goddard join Anderson Cooper to discuss Catherine’s medical fight ahead. Plus, at least 60 people are dead after an attack on a popular concert venue complex near Moscow. Former FBI Deputy Director Andrew McCabe and Dan Reed, director of the 2003 documentary "Terror in Moscow," join AC360 with their perspective on the attack. Learn more about your ad choices. Visit podcastchoices.com/adchoices