Lung cancer

What is this ?

Lung cancer, or bronchial cancer, affects more than 50,000 patients each year in France (52,777 new cases in 2023 according to data from INCa).

This cancer occurs as a result of the transformation of a normal cell into a cancerous cell in the lungs. It is the third most common cancer in women, with 19,339 new cases (after breast cancer and colorectal cancer), and the second most common in men, with 33,438 new cases (after prostate cancer).

Since 2010, the number of cases has been very slightly decreasing among men (-0.5% per year), but increasing significantly among women (+4.3% per year on average)

It is the leading cause of cancer death in France.

It is considered the second leading cause of cancer death in women behind breast cancer. It is the leading cause of cancer death in men. The median age at diagnosis of lung cancer in men is 68 years and 66 years in women.

Types of lung cancers:

Two types of bronchial cancers exist and are different both in appearance and management:

• Non-small cell lung cancer (NSCLC). It accounts for 85% of all lung cancers. In this category, the 3 most common subtypes are:
  • Adenocarcinoma
  • Squamous cell carcinoma
  • Large cell carcinoma

• Small cell lung cancer (SCLC). It affects 15% to 20% of patients with lung cancer.

Interview with Professor Fabrice Barlesi

Causes and risk factors

The risk factors for lung cancer are multiple and varied.

The primary risk factor is tobacco, which is considered the leading factor involved in the development of lung cancer and is responsible for 8 out of 10 lung cancers.

Environmental or occupational factors have an impact on the development of bronchial cancers. These include asbestos, exhaust gases, hydrocarbons, etc.

There is no hereditary transmission risk for lung cancer.

Tobacco and Cancer

Tobacco is responsible for 75,000 deaths, including 45,000 due to cancer, each year in France.

It is thus the most significant avoidable risk factor for cancer: it is estimated that, without tobacco, nearly one-third of cancer deaths could be avoided.

Tobacco causes 1 in 5 cancers, responsible for lung, bladder, colon, liver, pancreas, cervix, kidney, mouth cancers, etc.

Symptoms

The most common symptoms of lung cancer combine both respiratory issues and an unexplained decline in the patient’s overall condition:

• Persistent cough
• Shortness of breath
• Hoarseness or voice changes
• Unusual and persistent fatigue
• Presence of blood in sputum
• Loss of appetite
• Fever
• Unexplained weight loss
• Respiratory infections
• Significant, unexplained acute or chronic pain

Diagnosis

Different tests can diagnose lung cancer. The characteristics of the cancer help doctors decide which tests to perform: its histological type (the type of cells involved) and its stage (extent of spread).

To obtain a comprehensive diagnosis and understand all the characteristics of the cancer, the medical team will conduct various tests:

• Imaging for staging : this includes a chest X-ray, a CT scan of the chest, a CT scan or MRI of the brain, and a PET scan.
• Histological diagnosis : After a biopsy, the pathologist will analyze the tissues to determine the type and histological subtype of the cancer and identify any biological markers that may indicate prognosis and treatment response (such as PDL1). This biopsy may be performed via bronchoscopy, CT-guided needle biopsy, or surgical techniques.
• Molecular analysis : To search for potential mutations in the DNA of cancer cells that could guide treatment.

Treatments

Tobacco is responsible for 8 out of 10 lung cancers. The first part of the treatment will be to stop smoking completely.

Next, the oncologist will choose treatments based on several criteria:

• The type of cancer: Non-Small Cell Lung Cancer (NSCLC) or Small Cell Lung Cancer (SCLC)
• The stage of the disease: Stage I, Stage II, Stage III, Stage IV
• Whether the patient is operable or not
• Whether the tumor is resectable (i.e., can be removed through surgery) or not
• Specific molecular alterations: ALK, EGFR, ROS1
• The patient's overall health and other medical conditions

Treatment strategies for non-small cell lung cancers may include surgery, chemotherapy, radiation therapy, targeted molecular therapy (in the case of specific molecular alterations), and immunotherapy.

For small cell lung cancer, given its high tendency for dissemination, surgery is rarely performed. Treatment choices also consider whether the tumor can be irradiated and include chemotherapy, radiation therapy, and immunotherapy.