Lung cancer is one of the most common and serious cancers in the world. It is the second most common cancer in men after prostate cancer and the second in women after breast cancer. The main reason for its development is smoking, but can also occur in non-smokers.
With medical advances today, lung cancer can be detected earlier and treated successfully, greatly increasing the chances of survival.
What is lung cancer
The lungs are the organs that supply the body with oxygen and remove carbon dioxide. Lung cancer occurs when cells in the lung tissue begin to divide uncontrollably, forming malignant tumours that can spread to other organs.
There are two main types of lung cancer:
1. Non-small cell lung cancer (NSCLC)
This is the most common form, occurring in about 85% of cases. It includes several subtypes:
- Squamous cell carcinoma - originates from cells covering the airways.
- Adenocarcinoma - arises from the glandular cells that secrete mucus.
- Single cell carcinoma - characterized by large, abnormal cells that divide rapidly.
2. Small cell lung cancer (SCLC)
It accounts for about 15% of cases and develops rapidly, often metastasizing earlier than the non-small cell type. It is almost always associated with active smoking.
Symptoms of lung cancer
Lung cancer can go a long time without symptoms. In some patients, the disease is discovered accidentally on an X-ray on another occasion.
However, there are signs that should not be underestimated:
- Constant, persistent coughwhich intensifies over time
- Bloody phlegm
- Shortness of breath and wheezing
- Chest pain or in the shoulder
- Loss of appetite and weight
- Hoarse voice and difficulty swallowing
- Swelling of the face or neck
These symptoms can also be due to other diseases, but if they persist for more than a few weeks, it is important to see a doctor.
Causes and risk factors
1. Smoking
The main risk factor is tobacco. Cigarettes, cigars and pipes contain over 70 carcinogenic substances that damage lung tissue.
The risk increases with:
- the number of cigarettes per day,
- years of smoking,
- the depth of inhalation.
Stopping smoking can cut your risk in half after just 10 years.
2. Passive smoking
Non-smokers exposed to cigarette smoke are also at risk - especially at home and at work.
3. Exposure to harmful substances
- Asbestos - used in construction and insulation materials.
- Radon gas - a naturally occurring radioactive gas that can accumulate in buildings.
- Air pollution - especially in industrial areas.
- Arsenic in water and other chemicals also increase the risk.
4. Heredity and genetics
People with close relatives with lung cancer are more likely to develop the disease.
5. Previous lung diseases
Tuberculosis, chronic bronchitis, and pulmonary fibrosis can set the stage for cancer.
Diagnosis of lung cancer
Early detection is crucial for treatment success.
The diagnostic process involves several steps:
1. Imaging studies
- Chest radiography - initial method of detecting a suspicious mass.
- Computed tomography (CT) - determines the exact size, shape and location of the tumor.
- Positron emission tomography (PET-CT) - detects spread (metastasis) to other organs.
- Magnetic resonance imaging (MRI) - is used to assess spread in the brain or chest.
2. Biopsy
A tissue sample is needed to confirm the diagnosis:
- Bronchoscopy - through a thin tube inserted through the mouth or nose, samples are taken from the pulmonary tract.
- Needle biopsy - sample through the chest wall under CT control.
- Thoracocentesis - examination of fluid from the pleural cavity.
The resulting tissue is analyzed to determine the type and stage of the tumor.
Stages of lung cancer
Staging determines how advanced the disease is and how treatment will be carried out.
- I stages: The tumor is confined to the lung.
- Stage II: Nearby lymph nodes are affected.
- Stage III: Spread to the mediastinum (central part of the chest).
- Stage IV: Metastasis to other organs - liver, bone, brain, etc.
In small cell cancer, the division is simpler:
- Limited stage - only in one lung;
- Advanced stage - spread outside the lungs.
Treatment of lung cancer
Treatment is determined individually - according to the type, stage and general condition of the patient. A combination of different methods is the most common approach.
1. Surgical treatment
In early stages, surgery is performed to remove the tumor.
Types of surgical interventions:
- Segmentectomy or wedge resection - a small part of the lung is removed.
- Lobectomy - an entire lung lobe is removed.
- Pneumonectomy - the entire lung is removed in case of extensive tumours.
After the operation can be applied adjuvant therapy (chemo- or radiotherapy) to destroy any remaining cancer cells.
2. Chemotherapy
Drugs that destroy or stop the growth of cancer cells are used.
Chemotherapy can be administered:
- before surgery - to reduce tumor size;
- after surgery - to prevent relapse;
- as the main treatment at advanced stages.
Combinations of the two drugs are usually administered via the intravenous route or in tablet form. Side effects such as fatigue, nausea and hair loss are temporary and controllable.
3. Radiotherapy
It uses high-energy beams that destroy tumor cells.
Applicable:
- in patients who cannot be operated on;
- to relieve pain, shortness of breath and other symptoms;
- in combination with chemotherapy in locally advanced forms.
4. Target (intelligent) therapy
A modern method that uses drugs that target specific genetic mutations (e.g. EGFR, ALK).
These medications stop tumor growth with minimal side effects and are administered in tablet form. They are suitable for certain patients with non-small cell cancer.
5. Immunotherapy
Immunotherapy drugs activate the body's immune system to attack cancer cells.
This type of treatment, also called "cancer vaccine", is mainly used in advanced stage (IV) and can significantly prolong life.
Side effects are milder than chemotherapy, but may include temporary inflammatory reactions.
Prognosis and survival
The prognosis depends mostly on the stage at diagnosis:
- In the early stages, the chance of 5-year survival is about 50%.
- In advanced stages (with metastasis) it falls below 15%.
Early diagnosis through screening, especially in smokers over 50, is key to successful treatment.
How to prevent lung cancer
Lung cancer is among the most preventable cancers. Key measures include:
- Smoking cessation - even after years of smoking, stopping reduces the risk dramatically.
- Avoidance of passive smoke - do not allow smoking in your home or office.
- Use of protective equipment when working with asbestos and other toxic substances.
- Maintaining a healthy lifestyle - balanced nutrition, physical activity and weight control.
- Regular medical examinations - In people over 50 years of age and especially in active smokers, low-dose CT is recommended for early detection.
Frequently Asked Questions
How common is lung cancer?
Annually in the world are diagnosed over 1.3 million new cases. In Bulgaria, the number of patients is about 3000-4000 per year, with 80-90% of these related to smoking.
Can lung cancer be cured?
Yes - with early detection and proper treatment, a complete cure is possible, especially in the non-small cell type. In advanced stages, treatment can prolong life and improve its quality.
Can it develop in non-smokers?
Yes, about 15% of the patients had never smoked. For them it is more often genetic factors or exposure to radon, asbestos or polluted air.
Is there a vaccine against lung cancer?
There are immunotherapeutic drugs called "vaccines", but they do not prevent the disease, but serve as treatment for advanced cases. The Cuban and American versions differ in effectiveness and clinical evidence.
At what age does it occur most often?
Most often the disease is diagnosed between 55 and 70 years, but in recent years it has also occurred in younger patients due to early smoking initiation.
Conclusion
Lung cancer remains one of the most serious but also the most preventable cancers.
The most effective prophylaxis is the avoidance of tobacco smoke and regular check-ups.
Modern methods - surgery, chemo- and radiotherapy, targeted drugs and immunotherapy - give new hope and allow many patients to live long and fulfilling lives even after diagnosis.
