What to know about Pope Leo’s lung cancer

By Jen Christensen, CNN

(CNN) — Pope Leo XIV had surgery Tuesday at Agostino Gemelli University Policlinic in northwest Rome to remove a nodule that was determined to be pulmonary adenocarcinoma, the most common type of lung cancer.

The Vatican said surgeons removed the cancerous growth, along with the lower lobe of his right lung.

Pulmonary adenocarcinoma accounts for about 40% of all lung cancer cases. It’s a form of non-small cell lung cancer, and it usually grows and spreads to other parts of the body more slowly than small cell lung cancer does.

Surgery is typically the first step when someone has this form of cancer. The right lung, which is larger, has three sections called lobes, and the left has two; doctors will often remove the lobe the growth is found in to get rid of the tumor and to improve chances of a cure. The body eventually adapts to compensate for this loss of function.

It’s not always clear what causes this type of lung cancer. Although smoking can raise the risk, other risk factors include exposure to radon gas – the most common cause of lung cancer other than smoking – and particle pollution.

Pulmonary adenocarcinoma is most often diagnosed in people who have never smoked. It is also more common in women, younger patients and people of East Asian ancestry.

Adenocarcinoma is a leading cause of cancer-related death because doctors often don’t discover it until it’s at an advanced stage.

But on Sunday, the pope told a crowd that doctors had detected a growth in his lungs at “a very early stage.”

Based on what we know now, the pope should have a good prognosis, said Dr. Juanita Mora, the national medical spokesperson for the American Lung Association.

“The fact that Pope Leo had a localized case of adenocarcinoma with an early-stage detection works in his favor,” Mora said. “Especially after surgical removal.”

Mora said Leo’s recovery may be a “little bit longer” because the lungs will have to adjust to the removal of one lobe.

“Initially, it will be a little harder for him to breathe until the left lung starts to compensate for it,” Mora said. Having lessened lung capacity may not make much of a difference for his breathing.

Working in his favor, Mora said, is that the pope is not a smoker and is an otherwise healthy 71-year-old who plays tennis and exercises his lungs.

Mora said he will have to do respiratory therapy exercises. He also will need to be careful to avoid respiratory infections as best he can because they could affect him more without part of his lung.

She noted that Leo’s predecessor, Pope Francis, also had a lobectomy on his right side after 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.”

After this type of surgery, patients normally remain hospitalized for a few days until their vital signs and oxygen levels are stable, then typically continue recovering at home. Because it was a lobectomy, some pain is also expected.

Whether Leo can take a planned trip to Latin America next month will depend on what tests find in the next few days, Mora said.

In these cases, doctors examine samples from the lymph nodes around the lung, in addition to lung tissue, to determine the stage of the adenocarcinoma. Cancerous cells in the lymph nodes or any sign that the cancer has spread would help determine whether the pope needs treatment beyond surgery, such as chemotherapy or radiation.

Doctors also will conduct genetic and biomarker testing to determine how to treat the cancer further, if necessary. Knowing a person’s particular biomarkers can help target immunotherapy if needed.

Biomarker testing has significantly improved lung cancer treatment, Mora added, but in the US, only 15 states require medical insurers to cover such testing, even when someone has lung cancer.

“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 of Leo. “But now we will have to wait for these tests.”

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