Pope Leo XIV’s lung cancer diagnosis: Why pulmonary adenocarcinoma can go undetected for years

Pope Leo XIV has been diagnosed with lung adenocarcinoma, a common type of lung cancer, following surgery to remove the lower lobe of his right lung. What causes this cancer, can it affect non-smokers, and why is it often difficult to detect in its early stages?

Pope Leo XIV has been diagnosed with pulmonary adenocarcinoma, a form of lung cancer that can develop without noticeable symptoms in its early stages and can affect both smokers and non-smokers.

The 71-year-old underwent surgery at Rome’s Gemelli hospital to remove the lower lobe of his right lung. The Vatican said tests confirmed the diagnosis after doctors had suspected it during preoperative examinations. According to the AP, the Vatican described the surgery as successful, with no complications.

The diagnosis has drawn attention to pulmonary adenocarcinoma, the most common form of non-small cell lung cancer, and the challenges involved in detecting it early.

Quick answers to key questions

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QUESTIONS

It is a type of non-small cell lung cancer that develops in glandular cells, often in the outer regions of the lungs. It can affect smokers and people who have never smoked.

Yes. Smoking is a major risk factor, but the cancer is also diagnosed in people who have never smoked. Second-hand smoke, air pollution, radon and some workplace exposures can also increase risk.

It may grow for months or years without noticeable symptoms, particularly in its early stages. Sometimes it is found incidentally during imaging done for another medical reason.

Possible symptoms include a persistent or worsening cough, breathlessness, chest discomfort, coughing up blood, tiredness and unexplained weight loss. Early-stage disease may cause no symptoms.

Diagnosis may involve chest X-rays, CT scans, PET-CT imaging and a biopsy; molecular testing can identify changes that may guide treatment. Options depend on the cancer’s stage and other clinical factors and may include surgery, chemotherapy, radiation, targeted therapy or immunotherapy.

What is pulmonary adenocarcinoma?

Pulmonary adenocarcinoma develops in glandular cells of the lungs and commonly occurs in the outer regions of the lungs. It can grow for months or years without producing noticeable symptoms, making early detection difficult.

“Pulmonary adenocarcinoma is a type of lung cancer that tends to develop in the cells lining the lungs. It is a form of non-small cell lung cancer and can be commonly seen in smokers as well as non-smokers,” Dr. Sheeba Santhmayer, consultant radiation oncologist at TGH ONCO LIFE Cancer Centre, Talegaon told Mint.

Dr. Ashwani Kumar Sharma, vice chairman of Manipal Comprehensive Cancer Centre and Onco-Robotic Surgeries, said smoking remains the main risk factor, although the disease is also diagnosed in people who have never smoked.

Is lung adenocarcinoma linked to smoking?

Smoking is a major risk factor, but it is not the only one. Exposure to second-hand smoke, air pollution, radon gas and occupational carcinogens, including asbestos and diesel exhaust, can also increase the risk. Genetic factors may contribute in some cases.

Dr. Santhmayer cautioned against assuming that lung cancer affects only smokers or that an absence of symptoms means there is no risk.

What symptoms should people watch for?

According to Dr. Santhmayer, symptoms can include a persistent or worsening cough, breathlessness, chest discomfort, coughing up blood, tiredness and unexplained weight loss.

Because early-stage disease may not cause symptoms, it can sometimes be discovered incidentally during imaging performed for another medical reason. Persistent respiratory symptoms, particularly coughing up blood or unexplained breathlessness, warrant prompt medical evaluation.

How is pulmonary adenocarcinoma diagnosed and treated?

Diagnosis may involve chest X-rays, CT scans, PET-CT imaging and a biopsy to confirm cancer. Molecular testing can help identify genetic changes that may be targeted with specific treatments.

Treatment depends on the cancer’s stage, location and other clinical factors. Options include surgery, chemotherapy, radiation therapy, targeted therapy and immunotherapy.

According to AP, doctors had not yet reported the results of tests to determine whether Pope Leo XIV’s cancer had spread to his lymph nodes.

“Adenocarcinoma is the most common (type of lung cancer), also with the most favorable prognosis,” said Dr. Stephen Liu, a lung cancer expert at Georgetown’s Lombardi Comprehensive Cancer Center. “While we know the diagnosis we now need to know the stage."

Liu said further information about the tumour’s size, the number of affected areas and lymph node involvement would help determine the next steps in treatment.

About the Author

Anjali Thakur is a Senior Assistant Editor with Mint, reporting on trending news, entertainment and health, with a focus on stories driving digital conversations. Her work involves spotting early signals across news cycles and social media, sharpening stories for SEO and Google Discover, and mentoring young editors in digital-first newsroom practices. She is known for turning fast-moving developments—whether news-driven or culture-led—into clear, tightly edited journalism without compromising editorial rigour.<br><br> Before joining Mint, she was Deputy News Editor at NDTV.com, where she led the Trending section and covered viral news, breaking developments and human-interest stories. She has also worked as Chief Sub-Editor at India.com (Zee Media) and as Senior Correspondent with Exchange4media and Hindustan Times’ HT City, reporting on media, advertising, entertainment, health, lifestyle and popular culture.<br><br> Anjali holds a Bachelor of Arts degree from Miranda House, and is currently pursuing an MBA, strengthening her understanding of business strategy and digital media economics. Her writing balances newsroom discipline with a clear instinct for what resonates with readers.