Pope Leo's lung tumor raises questions about cancer risk for nonsmokers

Pope Leo XIV has been diagnosed with lung cancer after a scheduled surgery, the Vatican announced Tuesday.

After undergoing thoracic surgery, where surgeons removed the lower lobe of the popes right lung, examination of the tissue confirmed the diagnosis of lung adenocarcinoma.

The diagnosis had been suspected based on testing conducted before the procedure, according to the Holy See Press Office.

POPE LEO DIAGNOSED WITH LUNG CANCER AFTER SURGEONS REMOVE PART OF RIGHT LUNG, VATICAN SAYS

The pope reportedly and does not have a known history of smoking. The Centers for Disease Control and Prevention indicates that most lung cancer deaths (80%) are caused by smoking.

Lung adenocarcinoma is the most common type of lung cancer, representing about 40% of all lung cancers in the U.S., according to the Lung Cancer Foundation of America. It is also the most common type among non-smokers.

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In an interview with Fox News Digital, Lary Robinson, M.D., an oncologist at Moffitt Cancer Center in Tampa, Florida, shared his surprise regarding the popes , as the lung nodule was "felt to be malignant."

About 80% of lung cancers occur in people who smoke or have smoked, said Robinson, who has not treated the pope. However, he noted that lung cancer also occurs among never-smokers — including an estimated 10% of male patients and 25% of female patients.

"But [the pope] had surgery and had a lobectomy, so this is usually only done with people who have localized disease, and presumably he had localized disease. And hopefully that's a stage 1 cancer," the doctor added.

If the popes cancer is stage 1, there is a "high chance" of cure — about 90%, depending on the size of the tumor, the oncologist said. The fact that he went suggests there was likely no evidence that the cancer had spread.

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"We'll have to wait for the pathology to determine … whether he had a stage 1 cancer and whether he needs any afterward," Robinson said.

"Size matters in lung nodules and lung cancer – the larger the cancer, the worse outlook it is, because it's more likely to be advanced and have spread."

Not all lung cancer cases are caused by smoking. Other factors like family history and can play a role, experts say.

Recent research discovered that a rare genetic mutation in the gene EGFR T790M increased lung cancer risk by 25 times compared with people who did not have the mutation, according to findings published in the journal Science.

Among people who had never smoked, carriers of the mutation had about 62 times the odds of lung cancer compared with never-smokers who were not carriers.

Robinson added that other types of smoking, like pipes and cigars, can increase the risk of lung cancer, as well as heavy use of marijuana.

Another risk factor is exposure to environmental toxins, such as diesel exhaust and radon, according to the oncologist.

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