By Darko Obiri Stella
Lung cancer is a malignant tumor in which there is an uncontrolled growth of cells that line the lungs. There are usually no signs or symptoms in the early stages of lung cancer, but many people with the condition eventually develop symptoms including a persistent cough, coughing up blood, persistent breathlessness, unexplained tiredness and weight loss, pain when breathing or coughing
Risk factors associated with lung cancer include: Smoking, Exposure to asbestos, Secondhand smoke (passive smoking), Arsenic in drinking water, Family history of lung cancer
Types of lung cancer
There are two types of lung cancer;
¹Primary lung cancer: cancer that begins in the lungs.
²Secondary lung cancer: cancer that spreads to the lungs from other parts of the body.
Primary lung cancer can be classified into two main types depending on the type of cells in which the cancer starts growing. They are:
¹Non-small-cell lung cancer (NSCLC): This is the most common form of lung cancer, accounting for more than 87% of cases. It progresses slowly and is likely to have spread beyond the lungs by the time it is diagnosed. The main subtypes of NSCLC are adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. These subtypes, which start from different types of lung cells are grouped as NSCLC because their treatment and prognoses are often similar.
ᵃ⁾Adenocarcinoma: Adenocarcinomas start in the cells that would normally secrete substances such as mucus. This type of lung cancer occurs mainly in people who currently smoke or formerly smoked, but it is also the most common type of lung cancer seen in people who don’t smoke. It is more common in women than in men, and it is more likely to occur in younger people than other types of lung cancer. Adenocarcinoma is usually found in the outer parts of the lung and is more likely to be found before it has spread.
ᵇ⁾Squamous cell carcinoma: Squamous cell carcinomas start in squamous cells, which are flat cells that line the inside of the airways in the lungs. They are often linked to a history of smoking and tend to be found in the central part of the lungs, near a main airway or bronchus.
ᶜ⁾Large cell (undifferentiated) carcinoma: Large cell carcinoma can appear in any part of the lung. It tends to grow and spread quickly, which can make it harder to treat. A subtype of large cell carcinoma, known as large cell neuroendocrine carcinoma, is a fast-growing cancer that is very similar to small cell lung cancer.
²Small-cell lung cancer (SCLC): A less common form of lung cancer that usually spreads very fast. It is an aggressive form of lung cancer. It is characterized by the rapid, uncontrolled growth of certain cells in the lungs. Eventually, a tumor forms and cancer can spread or metastasize to other areas of the body.
The stage of lung cancer progression most often used for NSCLC is the TNM system, which is based on 3 key pieces of information:
• The size and extent of the main tumor (T)
• The spread to nearby lymph nodes (N)
• The spread (metastasis) to distant sites (M)
The stages are:
ᶦ⁾Occult stage: Cancer cells can be picked up in mucus that is coughed up. The cannot be seen on imaging scans or a biopsy. It’s also called hidden cancer.
ᶦᶦ⁾Stage 0: The is very small. Cancer cells haven’t spread into deeper lung tissues or outside the lungs.
ᶦᶦᶦ⁾Stage I: Cancer is in the lung tissues but not the lymph nodes.
ᶦᵛ⁾Stage II: The disease may have spread to lymph nodes near the lungs.
ᵛ⁾Stage III: The disease has spread further into more lymph nodes and the middle of the chest.
ᵛᶦ⁾Stage IV: Cancer has spread widely around the body. It may have spread to the brain, bones, or liver.
Treatment for lung cancer
Surgery: The type of surgery performed depends on where in the lung your cancer is, how big it is, and your general health.
Chemotherapy: Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells.
Radiation therapy: Radiotherapy uses high-energy x-rays to destroy lung cancer cells.
Targeted therapy: Immunotherapy and targeted drugs are sometimes used to treat stage 3 or 4 NSCLC
Photodynamic therapy: Photodynamic therapy kills cancer cells by using a combination of a light sensitizing drug and a very bright light.
Laser therapy: Laser therapy uses a focused beam of light to destroy cancer cells.
Microwave ablation: Microwave ablation uses high-frequency microwave energy to heat and destroy cancer cells.
Radio-frequency ablation: Radio-frequency ablation uses heat made by radio waves to destroy cancer cells.
Diathermy(electro-cautery): Diathermy treatment uses an electrical current to heat and destroy cancer cells.