JPMorgan Chase & Co. CEO Jamie Dimon

JPMorgan Chase & Co. CEO Jamie Dimon

Jason Alden/Bloomberg

Quarterly results may take a back seat to questions today about the health of Chief Executive Officer Jamie Dimon, 58, who said July 1 that he would soon undergo radiation and chemotherapy for throat cancer. While Dimon said his prognosis is excellent and he’ll be able to work during his eight-week treatment, the announcement raised fresh questions about succession planning at the bank he’s run since 2006.