Lung cancer

The causes of lung cancer are linked to genetic alterations in the cells of the respiratory tract due to repeated exposure to toxic products (carcinogenic substances), in most cases those contained in tobacco smoke (see Risk factors). These genetic changes encourage the appearance of cancerous cells, which can then multiply uncontrollably to form a malignant tumour.

There are two main types of bronchial carcinoma, which differ in their treatment and prognosis:

• non-small cell lung cancer ;
• small cell lung cancer.

Non-small cell lung cancer is by far the most common, accounting for over 80% of lung cancer cases. Small-cell lung cancer, on the other hand, is generally more aggressive than non-small-cell lung cancer and is often discovered at an advanced stage with metastases.

The prognosis for lung cancer therefore depends not only on the type of cancer but also on the stage of the tumour. In general, the more advanced the stage, the more extensive the cancer. Stage 1 cancer is a localised tumour with no lymph node involvement or metastases. Stage 4 cancer is more extensive and has metastasised to other organs, making treatment more complex and the prognosis less favourable.

Responsible for almost 80% of cases, smoking is the main risk factor for lung cancer. Tobacco smoke is also harmful to those around smokers (passive exposure), who are also at greater risk of developing cancer. Even after stopping smoking, the risk of developing lung cancer persists for years, although it is reduced by around half after ten years.

Exposure to many chemical substances, when inhaled repeatedly, can also increase the risk of lung cancer. These include radon, a radioactive gas naturally present in the ground that can concentrate in enclosed spaces, air pollution (fine particles) and asbestos.

There is also a genetic component, with people with a family history of lung cancer being at greater risk of developing it.

Lung cancer generally affects people over the age of 60. However, the more commonly known genetic forms, associated with a family predisposition, mostly affect younger people, before the age of 50.

In the early stages of the disease, lung cancer is often asymptomatic, which means that many tumours are only detected at an advanced stage. Signs of lung cancer may also be detected by chance during a routine imaging scan.

At a more advanced stage, symptoms may include:

The initial diagnosis is usually based on a chest CT scan. Additional tests, such as bronchoscopy, may also be necessary. This involves inserting an endoscope fitted with a camera into the bronchial tubes to view the suspect areas and taking tissue samples (biopsies) under local or general anaesthetic. It is also possible to remove lymph nodes located in the thoracic cavity to see whether the cancer has spread to the thorax. Finally, PET scans can be used to detect any metastases.

Lung cancer is treated mainly by surgery, radiotherapy and medication. If the tumour is well defined and not too extensive, it can be removed by surgery. If the tumour is more extensive, a combination of treatments may be used, including chemotherapy, targeted therapies based on certain genetic mutations, radiotherapy or immunotherapy. The aim of immunotherapy is to induce an immune response aimed at selectively destroying cancer cells. The choice of treatment depends on the type and stage of the cancer, as well as the patient's general condition. Treatment decisions are always discussed in multidisciplinary consultation.

Taking all types and stages together, the 5-year survival rate for lung cancer is around 20%. However, it is essential to stress that this figure depends largely on the type and stage of cancer at the time of diagnosis. Although the overall prognosis remains poor, considerable advances in treatment have improved survival rates in recent years. However, data beyond 2020 are not yet available, which limits precise assessment of the impact of new treatments on overall lung cancer mortality in Switzerland.

The key to preventing lung cancer is to stop smoking. This is the most effective way of reducing the risk of developing the disease, at any age. Giving up smoking not only reduces the risk of lung cancer, but also of other serious illnesses such as heart disease, circulatory problems and other cancers, particularly those of the oral cavity, oesophagus or bladder.

It is essential to consult a doctor if you experience any persistent or unusual symptoms, particularly if you are a smoker. These include a persistent cough, recurrent lung infections, shortness of breath, chest pain, bloody sputum or difficulty swallowing. More general signs, such as persistent fatigue, loss of appetite or weight loss, may also indicate lung cancer.

Hôpital de La Tour offers comprehensive care for lung cancer, with personalised treatments and tailored follow-up. Our multidisciplinary teams work together to choose the best therapeutic approach, taking into account the individual needs of each patient. In addition to medical treatments, a specific rehabilitation programme and nutritional monitoring are offered to improve patients' quality of life.

Can you get lung cancer if you don't smoke?
Although smoking is the main risk factor, around 15-20% of lung cancers occur in non-smokers. Risk factors include passive smoking, exposure to substances such as asbestos, radon or air pollution, and genetic predisposition.

Does stopping smoking protect against lung cancer?
Quitting smoking considerably reduces the risk of developing lung cancer: ten years after quitting, the risk is halved, and after twenty years of quitting, it is close to that of a person who has never smoked.

Is lung cancer hereditary?
Lung cancer can be genetically predisposed. These so-called genetic cancers generally affect younger patients (before the age of 50). The mutations responsible for these early forms may be hereditary, which justifies screening for those close to the affected patient.

Why can't I have my cancer operated on?
Whether or not a cancer can be operated on depends on its type and stage. For small-cell lung cancer, surgery is rarely considered. For well-defined non-small-cell lung cancer, surgery may be considered if the tumour can be completely removed and if the patient is fit to undergo the operation.