Louis Prevost, 74, the elder sibling of Pope Leo XIV, is currently hospitalized in Florida, receiving treatment for a recurrence of multiple myeloma, his wife Deborah Prevost disclosed to CBS News.
This revelation surfaced the same day the Vatican announced that Pope Leo XIV had undergone a successful surgery for a malignant lung tumor in Rome.
The simultaneous diagnoses within the Prevost family, made public within hours of each other, have thrust the brothers into the global spotlight.
Medical experts emphasize that there is no medical link between the pontiff's lung adenocarcinoma and Louis's multiple myeloma.
A Long Battle with Multiple Myeloma
Louis Prevost has been fighting multiple myeloma for nearly a decade, having first been diagnosed in 2017.
Two years ago, he underwent treatment involving stem cell therapy and participation in a clinical trial, which kept his illness at bay for several years.
However, the remission was not permanent. Deborah told CBS News that the disease spiraled out of control around three months ago.
Since then, Louis has been involved in a new clinical trial at a hospital near his home in Port Charlotte, southwest Florida. Deborah did not provide details on his current condition or prognosis, nor did she name the hospital.
A Family Under Pressure
Louis's wife described the family’s situation with poignant words. "We continue to pray and stay strong for both of them," she said, referring to her husband and the pope.
She acknowledged that the Prevosts are "going through a lot" and expressed hope that the pontiff’s cancer is in its earliest stage.
According to Infobae, the two brothers spoke by phone the week before the pope’s surgery, just as Louis was about to start his new clinical trial.
Deborah also mentioned that she has not heard of any radiation or chemotherapy planned for the pope.
Pope Leo XIV Successfully Operated in Rome
On Tuesday, Leo XIV was admitted to the Agostino Gemelli University Polyclinic in Rome for the removal of a lung nodule he had announced during the Angelus prayer on October 11.
"Doctors have identified a nodule confined to the lung. It was caught at a very early stage and is well localized," he stated.
The surgical team removed the lower lobe of his right lung using a video-assisted technique in a 90-minute procedure that concluded without complications.
The intraoperative histological examination confirmed the diagnosis of lung adenocarcinoma, the most common type of lung cancer, which has a favorable prognosis when detected early.
Future Steps Remain Uncertain
While the Vatican labeled the surgery as successful, the official statement did not specify the tumor's stage or whether the pope will require further treatments.
A Vatican source told AFP that additional post-operative tests were being conducted.
All of the pope’s appointments have been canceled until October 20, and he is expected to remain hospitalized for about a week.
Louis, Robert Francis—now Leo XIV—and their brother John grew up in Dolton, Illinois, a suburb south of Chicago.
Robert Francis was elected pope on May 8, 2025, becoming the first U.S.-born pontiff. Louis, the eldest, served in the U.S. Navy.
As the pope recuperates in Gemelli and his brother continues his clinical trial in Florida, the future of Leo XIV's pastoral tour through Latin America—planned for November 6 to 17, 2026, in Uruguay, Argentina, and Peru—remains officially unaltered.
Understanding the Prevost Family's Health Challenges
What type of cancer is Louis Prevost battling?
Louis Prevost is battling multiple myeloma, a type of blood cancer.
How does Pope Leo XIV's condition differ from his brother's?
Pope Leo XIV has been diagnosed with lung adenocarcinoma, which is unrelated to Louis's multiple myeloma.
What are the future plans for Pope Leo XIV's health care?
The Vatican has not detailed future treatments, but additional post-operative tests are being conducted.