Louis Prevost, the 74-year-old brother of Pope Leo XIV, is being treated for multiple myeloma at a Florida hospital. His wife, Deborah Prevost, confirmed the diagnosis on Tuesday, shortly after the Vatican announced that the 71-year-old pontiff is being treated for lung cancer.
The Vatican reported on Tuesday that Pope Leo XIV, born Robert Francis Prevost, underwent surgery to remove the lower lobe of his right lung. Doctors confirmed the lung cancer diagnosis following the procedure, though officials did not disclose the cancer's stage or whether it had spread. Pope Leo XIV is the first U.S.-born leader of the Catholic Church and was elected in May 2025.
Louis Prevost was originally diagnosed with multiple myeloma in 2017. According to his wife, he underwent stem cell treatment and a clinical trial in 2019, which kept the disease at a low level until he fell out of remission three months ago. He is currently enrolled in a new clinical trial at a local hospital.
Deborah Prevost stated that the two brothers spoke last week before Louis began his current treatment. She noted that the family was "going through a lot" but remained hopeful. The Vatican has not yet detailed what further treatments the pope may require, and Deborah Prevost said she had not heard of any specific plans for radiation or chemotherapy for the pontiff.
The public disclosure of the Pope's lung cancer diagnosis on Tuesday marks a period of medical uncertainty for the Vatican. The removal of a lung lobe is a major surgical event that typically requires a recovery period, which may alter the Pope’s schedule. The specific impact on Church administration depends on the undisclosed stage of the cancer and the nature of follow-up treatments, which have not yet been announced.
What happens next depends on the medical evaluations of both brothers. The Vatican has not provided a timeline for the Pope’s recovery or clarified when he will resume full duties. For Louis Prevost, the clinical trial at his local hospital will continue. No specific dates for further surgical procedures or additional health updates have been scheduled by the Vatican or the Prevost family at this time.