Lung cancer

Causes of Lung Cancer

• Lung cancer originates from chronically irritated bronchial cells, hence its name, “bronchogenic carcinoma.” It can occur in the large bronchioles near the lung apex or in the smaller bronchioles farther from the lung apex.
• Cigarettes are responsible for 80-90% of lung cancer cases. Smoking affects bronchial cell changes, leading to cancerous cell mutations. Heavy smokers are more than 10 times more likely to develop lung cancer than non-smokers. People who live close to smokers are at least twice as likely to develop lung cancer. If heavy smokers quit, their risk of lung cancer gradually decreases, but it takes over 10 years to reach the same level as non-smokers.
• Toxic substances: Exposure to asbestos, commonly used in the automotive industry, such as insulation, brake pads, clutches, construction, building structures, textiles, and mining, can increase the risk of lung cancer by up to 5 times. It can also cause mesothelioma, especially in those who also smoke. People with lung cancer are 90 times more likely to develop lung cancer than the general population. Other substances that can cause lung cancer include arsenic, nickel, chromium, and air pollution.
• Lung disease: People with a history of lung scarring, such as those with tuberculosis or emphysema, are at a higher risk of developing lung cancer than the general population.
• Other factors that increase the risk of lung cancer include increasing age, use of certain drugs, such as cocaine, vitamin A deficiency, and genetics.

What are the symptoms of lung cancer?

Respiratory symptoms include:

• Chronic cough, with or without sputum production
• Coughing up blood
• Wheezing and difficulty breathing due to the tumor growing, reducing lung space for breathing, or the tumor pressing on the bronchial tubes
• Chest pain during breathing
• Pneumonia and fever. However, these symptoms can also be caused by other lung diseases, and are not always symptoms of lung cancer.

Other systemic symptoms include:

• Loss of appetite, unexplained weight loss
• Swelling of the face, arms, neck, and upper chest due to venous congestion
• Hoarseness due to cancer spreading to nerves in the larynx
• Bone pain
• Difficulty swallowing due to cancer pressing on the esophagus
• Paralysis due to cancer spreading to the brain or spinal cord
• Lumps or lumps on the skin
• Neither of these symptoms may be lung cancer. Those experiencing the above symptoms should see a doctor to rule out other causes.

Factors Affecting Lung Cancer Prognosis

• Non-small cell lung cancer has a better overall prognosis than small cell lung cancer. Patients with early-stage lung cancer have a higher chance of complete cure and a higher survival rate than those with later-stage or metastatic disease.
• Patients with no severe underlying medical conditions or abnormal weight loss generally have better treatment outcomes than those with poor health.
• The correct treatment selection from the outset is crucial in predicting the outcome of the disease. Doctors can generally improve a patient’s quality of life, although sometimes they cannot completely cure the disease.

How many stages are there of lung cancer?

1. Small-cell lung cancer is divided into two stages:

• Limited stage: The cancer is found only in one lung and nearby lymph nodes.
• Extensive stage: The cancer has spread beyond the thoracic cavity on that side of the body, or from the lung to other organs in the body.

2. Non-small-cell lung cancer is divided into four stages:

Stage 1: The tumor is less than or equal to 5 centimeters in diameter and has not spread to lymph nodes.

Stage 2: The tumor is larger than 5 centimeters and has spread to the outer pleura and chest wall, or to lymph nodes near the tumor.
Stage 3: The tumor has grown larger and has spread to nearby organs, spread to other lung lobes on the same side, or spread to lymph nodes in the mid-thoracic cavity or beyond the tumor.
Stage 4: The cancer has spread beyond the thoracic cavity to a location far from where it originated. and cancer that spreads to the pleura or other organs such as lymph nodes in the neck, liver, bones, adrenal glands and brain, etc.

Lung Cancer Screening Methods

Screening in High-Risk Individuals: Currently, lung cancer screening is performed using a low-dose computed tomography (LDCT) scan in high-risk individuals.

History taking, physical examination, and special tests by a physician include: Chest X-rays, Computed Tomography (CT) scans, PET/CT scans, bronchoscopy and biopsies, mediastinoscopy, and CT-guided biopsies.

Lung Cancer Treatment Methods

1. Surgery: This is used to treat early-stage cancer that has not spread far or has spread only to nearby lymph nodes and has not spread to other vital organs. There are four types of surgery:

• Wedge resection: This surgery removes the tumor and surrounding tissue.
• Lobectomy: This involves removing the entire lobe of the lung.
• Pneumonectomy: This involves removing the entire lung.
• Sleeve resection: This involves removing the entire lobe of the lung and reattaching the adjacent bronchial tubes.

2. Radiation: This is a local treatment similar to surgery. The indications for these patients are as follows:

In patients with early-stage lung cancer who are ineligible for surgery, the results are similar to surgery.

In patients with locally advanced lung cancer (used in combination with chemotherapy) is the primary treatment for a complete cure. In patients with advanced lung cancer, chemotherapy is used in combination with chemotherapy to achieve a cure. This treatment is used in patients with stage III disease who have lymph node metastases and have not yet spread to nearby lymph nodes, making surgery impossible.

This treatment is used as an adjuvant treatment before and/or after surgery in patients with stage III disease for localized disease control. It is used as a palliative treatment in advanced cases, such as relieving bone pain and relieving pressure on blood vessels or important nerves, and relieving symptoms in cases where cancer has spread to the brain.
It is used as a treatment to prevent metastasis, such as radiation to the head, to prevent cancer from spreading to the brain.

3. Chemotherapy: Chemotherapy is the administration of drugs that destroy cancer cells by injection or intravenous infusion. The drugs pass through the circulatory system and reach the cancer cells through the blood vessels that supply the tumor. The advantage is that chemotherapy can penetrate all parts of the body within a relatively short period of time. However, it has side effects, such as nausea, vomiting, fatigue, loss of appetite, hair loss, sores in the oral mucosa, diarrhea, and a weakened immune system, making it more susceptible to and more severe than normal infections. Doctors will consider chemotherapy in the following situations:

After surgery, if the surgery reveals stage 2 (in some cases stage 1) cancer.

In combination with radiation therapy, it is used to treat locally advanced cancer.

To reduce the size of the tumor before considering other treatments. For stage 3 cancer, it is used to treat metastatic or recurrent cancer. The attending physician will always assess the patient’s physical fitness and suitability for chemotherapy.

4. Targeted Therapy: This is a cancer treatment that primarily targets the cancer cell but has only a minimal effect on normal cells. Most require genetic mutation testing before use. If abnormalities are found, this class of drugs, such as EGFR mutation testing and ALK fusion, can be used. Most drugs in this class are oral, have few side effects, and are more effective than chemotherapy.

5. Immunotherapy: This is the latest form of cancer treatment, using drugs to stimulate the body’s immune system to destroy cancer cells with few side effects. It is administered intravenously and may be used alone or in combination with other drugs, such as chemotherapy. The physician will determine the appropriateness of each patient’s drug use.

Prevention and Practices to Avoid Lung Cancer

• Quit smoking or avoid close contact with smokers.
• Avoid high air pollution, such as areas with heavy dust and smoke, or working in mines without protective equipment.
• Stay in clean air.
• Get regular physical exams.
• Exercise and eat a healthy diet to maintain good health.