Lung adenocarcinoma: Symptoms, risk factors and prognosis after Pope Leo's diagnosis

Pope Leo has been diagnosed with lung adenocarcinoma, the most common form of lung cancer.
The 71-year-old pontiff had been admitted to Rome’s Gemelli Hospital after doctors discovered a growth during a routine health check.
The diagnosis was made on Tuesday after doctors removed the lower lobe of his right lung during an operation.
Here are some key facts about the disease.
Adenocarcinoma is a type of cancer that forms in glandular cells, which produce substances such as mucus. In the lungs, it develops in cells lining the air sacs and is the most common subtype of non-small cell lung cancer (NSCLC), the category that accounts for about 80 to 85 per cent of lung cancers.
Adenocarcinoma represents roughly 40 per cent of all lung cancer cases, according to the Lung Cancer Foundation of America.
It is typically found in the outer parts of the lungs and tends to grow more slowly than some other forms of lung cancer, increasing the chances of detection before it has spread.
Smoking remains the main risk factor.
However, adenocarcinoma is also the most common type of lung cancer among people who have never smoked. The pope is not known to have been a smoker.
Early-stage disease often causes no symptoms and may be discovered during scans performed for other reasons. As the cancer progresses, symptoms can include a persistent cough, shortness of breath or wheezing, coughing up blood, chest, shoulder or back pain, unexplained weight loss and fatigue.
The Vatican has said the tumour was found during a routine health check.
Leo said on Sunday that the growth was “well-contained” and had been spotted early.
For patients whose cancer is confined to the lung, surgery offers the best chance of a cure.
The standard operation is a lobectomy, as occurred on Tuesday, in which an entire lobe of the lung is removed. Doctors consider it the preferred treatment when the tumour is limited to a single lobe because it maximises the chances of removing all cancerous tissue while preserving as much lung function as possible.
