Pope Leo XIV's brother Louis Prevost has cancer relapse, his wife says
Louis Martin Prevost, 75, the pope's older brother, is being treated for a relapse of multiple myeloma in Florida while Pope Leo XIV recovers in Rome from surgery for lung cancer
Two members of Pope Leo XIV's family are being treated for cancer at the same time. Louis Martin Prevost, 75, the pope's older brother, is undergoing treatment for a relapse of multiple myeloma, while the pope remains at the Gemelli Polyclinic in Rome after surgery for a lung adenocarcinoma.
Louis Prevost's condition was made public by his wife, Deborah Prevost, in comments to CBS News. She said the multiple myeloma was diagnosed in 2017. In 2019 he received a stem cell transplant and took part in a clinical trial, which kept the disease under control for several years. About three months before October 2026, he relapsed and had to resume treatment. He is now taking part in a new clinical trial at a hospital in Florida, where he lives with his wife.
Multiple myeloma affects the plasma cells in the bone marrow and is a different disease from the lung adenocarcinoma the pope has. Deborah Prevost also said the pope called his brother before he went into the hospital to tell him he would need surgery, even before the operation was announced publicly.
A family history of cancer
The three brothers grew up in Dolton, a town south of Chicago, in a family tied to education and to Catholic life. Cancer runs through the family history. Their mother, Mildred Agnes Martínez, worked as a school librarian and died on June 18, 1990, after suffering from cancer. Their father, Louis Marius Prevost, a World War II veteran who worked in education, died on November 8, 1997, though accounts differ over whether the cause was colon cancer or other natural causes.
Two of the three sons are now being treated for cancer at the same time.
Louis, veteran and public figure
Louis Martin Prevost was born on July 9, 1951, and is the eldest of the three brothers. A US Navy veteran, he came to public attention after his younger brother was elected pope in May 2025. Since then he has given several interviews about their shared childhood, the pope's personality and the bond between the three of them.
His conservative politics and his criticism of the Democratic Party have drawn media attention because of the ideological contrast with his brother, though the family relationship has remained intact. In the days before the pope's surgery, Louis Prevost spoke to the Italian newspaper Corriere della Sera and asked for prayers that the operation would go well. He later told Newsmax that his brother "was not in danger of dying and that doctors had caught the tumor in time." He was in Rome in May 2025 for the ceremonies marking the start of the pontificate.
John, the middle brother
The second brother is John Joseph Prevost, born on April 20, 1954, and now 72. He lives in New Lenox, in the Chicago metropolitan area, and spent much of his working life in Catholic education: 35 years in Catholic schools, 27 of them as a principal, before retiring.
John Prevost has kept a lower public profile than his brother Louis. After Robert Francis Prevost was elected pope, he gave several interviews about the brothers' childhood, their family life and Robert's early interest in religion.
Robert Francis Prevost: from the Augustinians to the Chair of Peter
Robert Francis Prevost, born on September 14, 1955, in Chicago, is the youngest of the three. An Augustinian who spent much of his religious life as a missionary in Peru, he was elected pope in May 2025 and became the first American pope.
Leo XIV, 71, had surgery on Tuesday, October 13, at the Gemelli Polyclinic in Rome after a lung nodule was found during a routine medical examination. The pope himself announced it during the Angelus on Sunday, October 11, saying it had been found at a very early stage. The operation lasted about 90 minutes and involved the removal of the lower lobe of the right lung. The diagnosis was lung adenocarcinoma.
Vatican News reported on October 15 that the pope had a good second night in the hospital and was able to get up and have breakfast. The previous day he had begun walking around his room, received respiratory physiotherapy and concelebrated Mass. Medical checks showed his recovery was within the expected range. The Holy See has not yet said whether he will need additional treatment such as chemotherapy or radiotherapy.
Prayer and hope
Deborah Prevost said the family stays in touch and is facing this period with prayer and hope, both for the pope's recovery and for her husband's treatment.
