Pope Leo XIV was released from the hospital on Saturday after undergoing surgery for lung cancer, telling supporters outside he was feeling “much better” as he was driven away in a black SUV.

The 71-year-old pontiff left Rome’s Agostino Gemelli University Hospital four days after surgeons removed the lower lobe of his right lung following his diagnosis of lung adenocarcinoma, a common form of lung cancer.

Leo was discharged three days before originally planned and the Vatican said he would still conduct noonday prayer from the window of the Apostolic Palace on Sunday. However, all his audiences have been canceled until Oct. 20.

Although the surgery was successful, it hasn’t yet been announced whether he will need further treatment, such as chemotherapy — raising a question few Catholics have had reason to consider: Who runs the Roman Catholic Church when the pope is sidelined by illness?  

Church law has no clear mechanism for temporarily transferring a pope’s authority if he becomes unable to perform his duties due to a medical issue, Rev. Patrick Flanagan, chair of St. John’s University’s theology department, told The Post.

“Church law does not provide for any emergency situations. If a pope were to be incapacitated, get sick, get dementia or be in the hospital for a period of time, there’s no real indication of who would be in charge,” Flanagan explained.

“One of the beautiful things about the Catholic Church is that it’s a well-run organization. Everyone has a place and everyone knows the responsibility. So the church continues.”

Thousands were gathered in St. Peter’s Square for Sunday noon prayer on Oct. 11 when the American-born pope announced from the Apostolic Palace window that he would be having an operation to remove a “localized nodule.”

That public announcement is unprecedented, as the Catholic Church has a history of keeping the health issues of popes shrouded in secrecy.

“I’m not convinced that there have been previous popes that have not been incapacitated that we knew nothing about. They just didn’t show up,” Flanagan said.

But the fact that the pontiff is the first US-born pope may have changed that, he added.

“One of his American traits is that he wants to be as transparent as he can be with the people of God in front of him. So I think he’s trying to balance transparency with privacy,” he said.

“For someone to tell you about their vulnerability is pretty remarkable … because, you’re not even two years into your job and you’re already dealing with health issues. And people are starting to worry — will this impact the rest of his pontificate?”

It was during a 90-minute surgery on Tuesday to remove a small nodule in his right lung that doctors found a malignant tumor and removed its lower lobe, and he was diagnosed with lung adenocarcinoma just 17 months after being elected in May 2025.

On Thursday, the Vatican said His Holiness “underwent routine checks, which yielded normal results,” adding that “the chest X-ray showed good recovery of the lung that underwent surgery.”

He also “carried out his daily activities independently,” including celebrating mass in the hospital, and “his physiotherapy session included a full range of physical activities.”

Thousands gathered in St. Peter’s Square the day after his surgery for a Mass that Pope Leo was scheduled to celebrate. Instead, Cardinal Luis Antonio Tagle, who was approved as the new dean of the College of Cardinals on Oct. 8 by Pope Leo, presided.

“The reaction has been overwhelmingly strikingly touching because people recognize that in just a short period of time that he’s been pope, he’s made such an incredible impact,” Flanagan said.

Pope Leo, whose name is Robert Francis Prevost, was admitted to the hospital during a weeklong Vatican summit of 200 including cardinals, bishops, experts and married couples from around the world, which ran from Oct. 7-14.

They convened on the 10th anniversary of Amoris Laetitia, a document written about love, marriage and sexuality by his predecessor Pope Francis, to discuss “topics ranging from cohabitation of young couples to influencers on social media portraying ‘traditional’ families, often referred to as ‘trad wife’ culture,” according to the National Catholic Reporter.

During the symposium, Pope Leo released a statement, saying: “As you know, I have been unable to be among you during these days. I thank you warmly for your prayers and for the work you have done together. Your sharing of experiences and attentive listening are indeed a gift to the whole Church. I ask you please to pray for me, as I pray for you.”

On Tuesday, Pope Leo was supposed to travel to Castel Gandolfo, 15 miles from Rome, to present a sustainability medal in his name on behalf of his alma mater, Villanova University, during its International Sustainability Conference. Villanova’s president, Rev. Peter M. Donohue, presented the medal to its inaugural recipient, Cardinal Michael Czerny, in his absence.

It was also rumored the pope would attend the Villanova basketball game in Rome against Notre Dame dubbed the Eternal City Tip-Off on Nov. 1 at the Palazzo dello Sport. Ahead of the game, on Oct. 31, there will be a private Mass at St. Peter’s Basilica celebrated by Archbishop Nelson J. Pérez, followed by a planned audience with His Holiness at St. Paul VI Audience Hall.

From Nov. 6-17, he is booked for a trip to Uruguay, Argentina and Peru, where he served as Bishop of Chiclayo from 2015 to 2023. The trip would be 19,000 miles over 12 days and include 14 flights, and Flanagan explained its significance.

“I think the South American trip is so important because we saw his trip to Paris did,” Flanagan said of the pontiff’s visit to the City of Light, which drew a record-breaking crowd of around 800,000.

“I mean, it really revolutionized the reality of that city.”