JP Morgan CEO Jamie Dimon has been diagnosed with throat cancer and will soon begin treatment in New York City. A biopsy, a CT scan and a PET scan confirm that the cancer is confined to his throat. Dimon's announcement came on his 10-year anniversary at the bank. Although the treatment will take eight weeks, Dimon says he will continue to be actively involved in his daily work during that time. No one expects Dimon to retire just yet, but speculation on who will replace him, if and when he leaves his role, is rising. One name that comes up often is Gordon Smith. Smith worked at American Express for 25 years, and joined JP Morgan in 2007. He now runs Chase, overseeing nearly 170,000 employees, from mortgage originators to call center employees, making him well-prepared to run a large, diverse organization. Another candidate is Matt Zames. He's a trader, best known for taking care of the aftermath of the London Whale disaster. His background is in hedge funds, which may be why he isn't viewed as the top candidate. Mary Erdoes, the head of asset management, is also a contender. She oversees $2.3 trillion and has been with JP Morgan for nearly two decades. Of course, the board could hire someone from the outside. There are well-respected executives at firms comparable in size who could also enter the race.