Pope Leo XIV’s brother diagnosed with cancer as pontiff undergoes surgery

Pope Leo XIV’s family is facing a difficult period after his elder brother, Louis Prevost, was diagnosed with active multiple myeloma, a type of blood cancer, as the pontiff undergoes treatment for lung cancer.

Louis, who lives in Florida, was first diagnosed with the disease in 2017. His wife, Deborah Prevost, confirmed his condition in an interview with CBS News on Tuesday, October 13, 2026.

According to Deborah, Louis underwent treatment in 2019, including stem cell therapy and participation in a clinical trial. His cancer subsequently remained at a low level before returning to an active state about three months ago after he fell out of remission.

He is currently receiving treatment through another clinical trial at a local hospital. Deborah did not disclose the current stage of his cancer but said the family was relying on prayer as the two brothers faced their respective health challenges.

“He called to let us know what would be happening,” Deborah told CBS News, referring to Pope Leo’s communication with the family before Louis began his latest clinical trial.

“We keep praying, keeping spirits up for both of them,” she added.

The news about Louis comes as Pope Leo XIV, 71, undergoes recovery following surgery at Rome’s Gemelli Hospital after doctors discovered a cancerous growth in his right lung.

The pontiff had earlier revealed that medical examinations had detected a small, localised nodule in his lung, prompting doctors to recommend surgery.

During the procedure, doctors removed the lower lobe of his right lung after examination confirmed the presence of lung adenocarcinoma, a type of lung cancer.

The surgery lasted approximately 90 minutes, although the pontiff spent about three hours in the operating room. He regained consciousness normally and was taken to his hospital room to recover.

The Vatican has not disclosed the stage of the cancer or whether it has spread beyond the lung. Further examination of the removed tissue is expected to help doctors determine whether additional treatment will be necessary.

Pope Leo, born Robert Francis Prevost in Chicago, became the first American-born pope when he was elected leader of the Catholic Church in May 2025, following the death of Pope Francis.

With both brothers now facing cancer diagnoses, the family is relying on prayer and hoping for their recovery as they navigate the difficult period.