In 2023, the number of new lung cancers has been estimated at 52,777 in France. This cancer is the second most common in men and the third in women. There are two main groups of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). “Approximately 85% of patients who have lung cancer have non-small cell cancer and 15% of patients have small cell cancer. To find out what type of lung cancer a patient has, a biopsy is performed.“, indicates Dr Pernelle Lavaud, medical oncologist and member of the thoracic oncology center at the Gustave Roussy Institute.
Lung cancer: common risk factors
The first risk factor of lung cancer, whether small cell or non-small cell, is smoking but cannabis consumption is increasingly incriminated. “We have the impression that heavy cannabis users develop lung cancer at a slightly younger age. There atmospheric pollution can also be incriminated just like the radon which is the main risk factor in non-smokers“, specifies Doctor Lavaud.
Radon is a radioactive gas derived from uranium naturally contained in the earth’s crust which can concentrate to high levels in poorly ventilated enclosed spaces. Its concentration is higher in regions with granitic or volcanic basements such as the Massif Central, Brittany, the Vosges, the Pyrenees, the Alps and Corsica. Other risk factors for lung cancer include occupational exposure to toxic products. “This is the case for professionals who work with toxic products, for example woodworkers or people who handle heavy metals such as chromium or nickel. Now professionals at risk wear masks to protect themselves, but this was not the case 30 years ago.“, notes Dr. Lavaud
Non-small cell lung cancers: targeted therapies
Non-small cell lung cancer develops from cells lining the walls of the bronchi, bronchioles and alveoli. There are three main types of non-small cell lung cancer: adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Adenocarcinoma is the most common lung tumor and develops from cells of the glandular epithelium located on the walls of the mucus-producing glands that line the airways. The second most common NSCLC, squamous cell carcinoma develops from the epithelial cells of the lung linings proximal to the bronchial tree. Finally, accounting for 10 to 15% of non-small cell lung cancers, large cell carcinoma can develop from any lung cells. The main risk factor for NSCLC is smoking and its most common symptoms are persistent or worsening cough, sputum with traces of blood, difficulty breathing, pain, weight loss, lack of appetite and significant fatigue.
“Treatment is based on first-line surgery when the disease is localized. There radiotherapyoften associated with chemotherapy, can be an alternative to surgery when this is not feasible. Treatments for metastatic disease include chemotherapy,immunotherapy and targeted therapies. THE targeted therapies are treatments that can be administered orally or venously depending on the type of molecule. They recognize cells that have a particular mutation and kill them. The most common cancer mutations are EGFR and KRAS mutations“, explains Dr. Lavaud. “Non-small cell lung cancer secondarily progresses less quickly than small cell lung cancer and therefore has a better prognosis.“, she adds.
Small cell lung cancers: rapid progression
Small cell lung cancer is a cancer of the neuroendocrine cells of the bronchi. Its main risk factor is smoking and it has the same symptoms as non-small cell lung cancer. “Small cell lung cancers very rarely have mutations unlike NSCLC. They are therefore not treated with targeted therapies but by radiotherapy and chemotherapy in the event of localized disease, and at the metastatic stage with chemotherapy and immunotherapy.“, explains Dr. Lavaud. “This type of lung cancer is initially very sensitive to chemotherapy. In general, there is a rapid reduction in the size of the lung tumor and also metastases. The problem is that it is a cancer which then progresses rapidly under treatment.adds Dr. Lavaud.
Read also:
⋙ What are the main causes of lung cancer?
⋙ Lung cancer: the incidence in women is catching up with that in men, why this worries scientists
⋙ Lung cancer and immunotherapy: principle, effectiveness, for whom?