Lung cancer remains one of the leading causes of cancer-related death worldwide and is also one of the diagnoses people fear most. For that reason, it is important to dispel some of the misconceptions surrounding the disease and understand, in simple terms, what modern medicine can offer today. We almost automatically associate lung cancer with smoking, and for good reasons: more than 80% of cases are linked to tobacco exposure and smoking. However, the remaining 20% remind us that other factors are also involved, including pollution, occupational exposure and age. Lung cancer is the focus of another episode of the Hospital da Luz podcast DECIPHERING CANCER , featuring João Moreira Pinto , Medical Oncologist at Hospital da Luz Lisboa, who has devoted much of his professional life to the diagnosis, treatment and research of this disease. What exactly is lung cancer? Lung cancer occurs when a cell stops following the normal rules of growth, multiplication and programmed cell death that regulate all the cells in our body. These control mechanisms ensure that cells grow when necessary and are removed when they are no longer needed. When a lung cell loses this natural brake, it begins to multiply uncontrollably until it forms a nodule, a mass or a tumor. What causes have been identified? More than 80% of lung cancer cases are associated with tobacco exposure and smoking. But 80% is not 100%: tobacco smoke exposure is not always obvious. Environmental exposure, for example, can play a role, as can other known factors such as pollution, exposure to heavy metals, mining work and chronic lung diseases. Age is also an important factor. Over time, the mechanisms that correct errors in cell replication become less effective, making it easier for cells to lose this natural brake. Is lung cancer hereditary? Unlike breast or ovarian cancer, where well-known hereditary mutations such as BRCA have been identified, lung cancer does not have clearly established hereditary mutations .That said, having a first-degree relative, such as a parent, sibling or child, with lung cancer does increase a person's likelihood of developing the disease. This may be explained either by shared environmental or occupational exposures within families or by as-yet unidentified inherited mutations. In any case, hereditary mechanisms are rare and are far from being among the main risk factors. What warning signs should people be aware of? The problem with most symptoms of lung cancer is that they may also result from benign conditions. Coughing, sputum production and some shortness of breath are common symptoms of respiratory infections and usually resolve within a few weeks. Coughing up blood is a more specific warning sign. The key issue is persistence: when symptoms last for months rather than weeks, it is time to seek medical advice. Can lung cancer be detected early? Is there screening? Portugal does not yet have a nationwide lung cancer screening programme , but evidence shows that in people who smoke or have smoked, low-dose CT screening, typically performed between the ages of 50-55 and 75, reduces mortality from this disease. Initiatives already exist in Portugal, including at Hospital da Luz Arrábida , and it is expected that such programmes will identify increasing numbers of cases at an early stage, when the chances of cure are greater. Can pneumonia turn into lung cancer? No. Pneumonia is an infection, not a neoplastic cell. What can happen is the opposite: a pre-existing lung nodule may become infected and cause pneumonia, with medical imaging showing only an area of abnormality. This is why reassessment after the pneumonia has resolved is important. If the nodule remains, further investigation is required. How is lung cancer diagnosed? When a suspicious lung nodule is identified, the first step is to determine whether the disease is confined to the lung or has already spread to lymph nodes or other organs. Tests such as positron emission tomography (PET) , which identifies areas of increased glucose consumption characteristic of tumors, and brain MRI are used for this purpose. The tumor type must then be confirmed through a biopsy, performed either through the chest wall with a needle or endoscopically, depending on the location of the lesion. Only with this information can doctors determine the stage of the disease and decide on the most appropriate treatment. And while we are on the subject: eating sugar does not make cancer grow faster. Excessive sugar consumption over many years may increase the risk of several cancers, but an occasional sweet treat has no meaningful impact once a diagnosis has been established. What treatments are available today? Not all lung cancers are the same. There are two major groups: non-small cell lung cancer, the most common form, and small cell lung cancer, which accounts for around 15% of cases and is generally more aggressive, requiring different treatment approaches. For most patients, prognosis depends heavily on the stage of the disease. A small tumour that can be surgically removed has a very high cure rate, whereas advanced disease is far more difficult to cure. However, lung cancer is one of the areas of oncology that has evolved most dramatically over the past two decades. We now know that each tumor may harbor different mutations, and for many of these mutations targeted therapies are available, providing much more precise treatment than was possible twenty years ago. Even patients without these mutations now have more options through immunotherapy. What are the most common side effects of treatment? Contrary to popular belief, not all patients experience severe side effects . In fact, preserving quality of life is one of the goals of treatment. Side effects depend on the type of therapy. Chemotherapy can affect healthy fast-dividing cells, causing symptoms such as reduced immunity, anemia, nausea or loss of appetite. However, supportive treatments to manage these effects have improved significantly over the last twenty years. Immunotherapy works by activating the immune system against the tumor and, in some cases, may also affect healthy tissues, leading to autoimmune conditions. Targeted therapies aimed at specific mutations may cause skin-related side effects, including rashes and irritation. What follow-up is required after treatment? For patients who undergo surgery or radiotherapy, follow-up includes blood tests and periodic CT scans, initially every six months and then annually, for at least five years. In patients with more advanced diseases receiving systemic treatment, follow-up is primarily aimed at determining whether the therapy remains effective. Regarding immunotherapy, most studies limit treatment duration to two years, although the optimal length is still not fully established. In many cases, the immune system learns to recognize the tumor and continues to fight it even after treatment has stopped. What does Hospital da Luz offer these patients? Treating lung cancer requires a multidisciplinary team, including pulmonologists, surgeons, radiologists, nuclear medicine specialists, oncologists and pathologists, who discuss all cases weekly, enabling faster diagnoses and treatment decisions. Rapid access to specialized diagnostic tests, such as PET scans and endobronchial ultrasound (EBUS), is also essential. Patients may also have access to clinical trials, allowing them to receive innovative therapies years before they become widely available. In Portugal, even after approval by European authorities, new medicines take, on average, more than two years to reach patients. There are many different types of cancer. Some have a better prognosis, others are more challenging; some responses to treatment are rapid, while others require more time and patience. But if there is one message worth remembering, it is this: more than 80% of lung cancer cases remain linked to tobacco use, and stopping smoking, at any age, always reduces risk. And for those facing a diagnosis, it is important to know that what medicine can offer today is far better than it was ten or fifteen years ago, and that in five or ten years' time it will, likely, be even better. Key Takeaways More than 80% of lung cancer cases are linked to tobacco use. A cough, sputum production or shortness of breath that persists for months rather than weeks should be assessed by a doctor. In current or former smokers, low-dose CT screening (ages 50-75) can reduce lung cancer mortality. Treatment and prognosis depend largely on the stage and type of tumor and are becoming increasingly personalized. Access to clinical trials allows patients to benefit from innovative treatments years before they become widely available. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item. English translation generated with AI and reviewed by the editorial team
