Pope Leo XIV is eating normally and recovering as expected after surgery Tuesday at Agostino Gemelli University Policlinic in northwest Rome. Surgeons removed a cancerous nodule and the lower lobe of his right lung after the growth was identified as pulmonary adenocarcinoma.

The pope underwent a biopsy before the nodule was removed. On Wednesday, the Vatican said blood tests and a scheduled chest X-ray showed that his recovery was proceeding normally after the operation.

Leo had already begun respiratory physiotherapy, and hospital workers helped him get up and walk around his room. Such exercises can help strengthen the lungs as his body adjusts to the loss of one lobe.

Pulmonary adenocarcinoma represents about 40% of all lung cancer cases. It is a form of non-small cell lung cancer that generally grows and spreads to other parts of the body more slowly than small cell lung cancer.

Surgery is typically the first treatment for this form of cancer. The larger right lung has three sections called lobes, while the left lung has two, and doctors often remove the lobe containing the growth to eliminate the tumor and improve the chance of a cure.

The body can eventually adapt to the resulting loss of lung function. Dr. Juanita Mora, national medical spokesperson for the American Lung Association, said Leo’s recovery could take a “little bit longer” while his lungs adjust.

“Initially, it will be a little harder for him to breathe until the left lung starts to compensate for it,” Mora said. She added that the reduced lung capacity may not make much difference to his breathing over time.

Although smoking raises the risk of pulmonary adenocarcinoma, the disease is most often diagnosed in people who have never smoked. Other risk factors include radon gas, described as the most common cause of lung cancer besides smoking, and exposure to particle pollution.

The cancer is also more common among women, younger patients and people of East Asian ancestry. Lung cancer is typically diagnosed at an average age of around 70, and adenocarcinoma is a leading cause of cancer related death because it is often discovered at an advanced stage.

Leo, however, told a crowd Sunday that doctors had detected the growth at “a very early stage.” Mora said the localized cancer and early detection work in his favor, particularly after surgeons removed the affected tissue.

The pope is not known to have smoked and is an otherwise healthy 71 year old who plays tennis and regularly exercises his lungs. He was also previously known to have had a personal trainer while serving as a cardinal.

Mora said Leo should try to avoid respiratory infections because they could have a greater effect after the removal of part of his lung. She also noted that Pope Francis had a lobectomy on his right side following a severe tuberculosis infection when he was young.

“So obviously, a lot of people live and can fully do everything in terms of function and capacity, even with a lobectomy,” Mora said. Patients usually remain hospitalized for several days after this operation until their vital signs and oxygen levels are stable, then continue recovering at home.

Doctors will examine nearby lymph nodes and lung tissue to determine the cancer’s stage. Cancer cells in the lymph nodes or evidence of spread would help determine whether Leo needs additional treatment, including chemotherapy, radiation, immunotherapy or another targeted approach based on genetic and biomarker testing.

“We’re hoping, though, that it’s just an isolated cancer where he’s one and done, in which now we see a survival rate of 80% to 98% when it comes to surgical removal,” Mora said. “But now we will have to wait for these tests.”

Doctors are confident the cancer was removed, although they are awaiting results to confirm that it did not spread. Dr. Otis Brawley said that if the nodule was the only cancer and measured less than 3 centimeters, Leo would be monitored with periodic CT scans.

“His chances of a full recovery are excellent,” Brawley, the Bloomberg distinguished professor of oncology and epidemiology at Johns Hopkins University, said in an email. “Especially given he is in good physical shape to begin with.”