Pope Leo XIV has reportedly been diagnosed with lung adenocarcinoma, a type of lung cancer, following surgery to remove a nodular lesion from his right lung, as his older brother, Louis Prevost, continues treatment for multiple myeloma in Florida.
The Vatican confirmed the Pope’s diagnosis after he underwent surgery on Tuesday. However, details about the stage of the cancer, whether it has spread and the treatment plan have not been disclosed.
Louis’ wife, Deborah Prevost, said her husband is currently participating in a clinical trial at a local hospital as he receives treatment for multiple myeloma, a cancer that affects plasma cells responsible for producing antibodies.
Louis was first diagnosed with the disease in 2017. According to Deborah, treatment in 2019, which included stem cell therapy and participation in a clinical trial, helped keep the cancer at a very low level.
However, he reportedly fell out of remission about three months ago, prompting renewed treatment.
Deborah said she could not comment on the specifics of the Pope’s condition but revealed that the two brothers spoke last week before Louis underwent his latest clinical trial.
She said the family was relying on prayer and maintaining a positive outlook as the brothers faced their respective health challenges.
The family is hopeful that the Pope’s cancer was detected at an early stage, although the Vatican has not confirmed the extent of the disease or indicated whether further procedures, chemotherapy or radiation therapy will be necessary.
Pope Leo XIV, 71, made history in May 2025 when he was elected the first United States-born leader of the Catholic Church. Born Robert Francis Prevost, he grew up with his two older brothers, Louis and John, in the Chicago area.
Louis previously recalled that his younger brother showed an early interest in religious life. While other children played baseball and other childhood games, Robert preferred playing priest, which Louis viewed as an early indication of his religious calling.
Despite his brother’s election as Pope, Louis said he would continue treating him as a younger sibling, preserving the family bond they shared long before Robert assumed leadership of the Catholic Church.
The reported diagnoses have drawn attention to the brothers’ health as Catholics around the world await further information about the Pope’s condition and recovery.
