Lung cancer is one of the most popular and deadly types of cancer in the world. It is a malignant tumour that starts in the lung tissues. It is the cause of millions of deaths every year, more than the combined deaths from colon, breast, and prostate cancer.
This article will provide a complete understanding of lung cancer, a common and dangerous medical condition, by examining its symptoms, causes, and treatment.
Lung Cancer
Lung cancer is a type of cancer that originates in the tissues of the lungs, typically in the cells lining the air passages. It occurs when abnormal cells in the lung grow and lead to the formation of a tumour. Smoking, exposure to carcinogens, genetic predispositions, and other factors can all cause lung cell mutations that lead to the development of these abnormal cells.
Compared to normal cells, which go through a controlled process of growth and death, cancer cells proliferate without the usual regulatory mechanisms. It can result in masses or tumours that can block the airways and affect lung function.
Symptoms of Lung Cancer
In its early stages, lung cancer often does not produce noticeable symptoms, making early detection difficult. These symptoms can include:
- Persistent Cough: One common early symptom is a persistent new cough or a chronic cough that gets worse with time.
- Chest Pain: Felling of unease or pain in the chest, especially during deep breathing, coughing, or laughing.
- Difficulty Breathing: Breathing problems or coughing can happen when the tumour grows and blocks the respiratory system.
- Hoarseness: If cancer affects the trachea or nearby nerves, vocal changes or hoarseness may result.
- Weight Loss: Unexplained weight loss accompanied by loss of appetite.
Advanced Symptoms
The symptoms worsen and become more complex as the cancer spreads:
- Hemoptysis: Coughing up blood or vomit that is rust-coloured.
- Bone Pain: When cancer advances to the bones, particularly in your legs or back, it can cause pain.
- Headache and Neurological Symptoms: If the cancer spreads to the brain, severe headaches, dizziness, or neurological symptoms may occur.
- Pleural Effusion: The fluid accumulation around the lungs causes increased breathlessness.
- Fatigue: Persistent and severe tiredness not relieved by rest.
Paraneoplastic Symptoms
Lung cancer can also lead to paraneoplastic symptoms, where the cancer affects distant organs and tissues indirectly:
- Hypercalcemia: Increased blood calcium levels can result in symptoms such as dizziness, nausea, vomiting, and constipation.
- Cushing Syndrome: High levels of cortisol lead to high blood pressure, weight gain, and skin changes.
- SIADH: Syndrome of Inappropriate Antidiuretic Hormone Secretion, causing low sodium levels, leading to weakness, confusion, and seizures.
Causes of Lung Cancer
The primary cause of lung cancer is exposure to carcinogens, with tobacco smoke being the most significant risk factor. The causes and risk factors include:
Tobacco Smoking
Tobacco smoking is the dominant cause of lung cancer, responsible for approximately 85% of cases. The cigarettes smoked daily and the overall time spent smoking increases an individual’s risk of developing lung cancer. Cigarette smoke contains over 7000 chemicals, 80 of which are carcinogens. These substances harm lung cells, causing mutations and the emergence of cancer.
Secondhand Smoke
Lung cancer risk is also increased by secondhand smoke exposure. Non-smokers living with smokers are at higher risk due to breathing in the smoke from the burning of a cigarette and the smoke exhaled by smokers. Young children and babies who are exposed to secondhand smoke are particularly vulnerable because of the harm that can occur to their developing lungs.
Radon Exposure
Another significant cause of lung cancer is radon, a radioactive gas inherent in rocks and soil. Lung cancer can result from chronic exposure to high radon levels, particularly in smokers. Residents who live in areas where soil radon levels are higher are at a higher risk. One of the most important ways to lower the risk of radon-related lung cancer is to test for radon and mitigate high levels in homes.
Carcinogenic Substances
Occupational exposure to carcinogens like asbestos, arsenic, and certain other chemicals can increase the risk of lung cancer. Workers in high-risk industries, including mining, construction, and chemical manufacturing, are particularly vulnerable. Without proper safety precautions, frequent exposure to these dangerous substances can increase the risk of severe health problems, including lung cancer.
Air Pollution
Lung cancer risk has been associated with long-term exposure to air pollution outstanding particulate matter (PM2.5). Pollutants from industrial processes, automobile emissions, and home heating increase this risk. Reducing air pollution is a public health priority because it poses a threat to global health due to its association with lung cancer as well as its role in respiratory and cardiovascular disorders.
Genetic Factors
An individual’s risk of developing lung cancer may be increased by a family history of the disease, which indicates a possible genetic factor. Lung cancer risk has been linked to mutations in specific genes, including ALK (anaplastic lymphoma kinase) and EGFR (epidermal growth factor receptor).
Types of Lung Cancer
Lung cancer is widely grouped into two main types:
Non-Small Cell Lung Cancer (NSCLC)
Non-Small Cell Lung Cancer (NSCLC) is the most widespread type, representing about 85% of all lung cancer cases. It includes subtypes such as adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. NSCLC usually develops and spreads more slowly than SCLC.
Symptoms can include chest pain, persistent cough, and shortness of breath. Diagnosis typically involves imaging tests and biopsies. Early detection is crucial for improving outcomes.
Small Cell Lung Cancer (SCLC)
Approximately 15% of cases of lung cancer are small cell lung cancer (SCLC), which is closely associated with smoking. SCLC spreads quickly to other body parts and is frequently discovered only after dissemination. It is well-known for its quick growth and tendency to metastasise early.
It can be divided into two categories: limited-stage, which is controlled by localised treatments and confined to one lung and adjacent lymph nodes, and extensive-stage, which spreads outside the lung and requires systemic therapies.
Treatment Options for Lung Cancer
Treatment of lung cancer mainly depends on its type and stage. The treatment options include:
Surgery
The chief treatment for early-stage lung cancer is surgery, which tries to remove the tumour and surrounding tissue to stop the cancer from spreading. Tumour location, size, and patient health all affect the surgical options.
Lobectomy removes an entire lung lobe, balancing complete tumour removal with lung function preservation. Pneumonectomy removes a whole lung and is reserved for extensive cancers. Segmentectomy and wedge resection remove part of a lobe or a small section of the lung, aiming to preserve healthy tissue while eliminating cancerous cells.
Radiation Therapy
When treating lung cancer, radiation therapy offers a flexible approach by using high-energy rays to target and kill cancer cells specifically. It can be used as the primary treatment for those who are not surgical candidates or in combination with chemotherapy and surgery to improve results.
With minimal harm to healthy tissue, external beam radiation precisely targets tumours from the outside of the body. Also, by controlling symptoms like breathing problems, radiation therapy offers supportive care to reduce pain and enhance quality of life.
Chemotherapy
Chemotherapy is the primary source of treatment for advanced lung cancer and involves the use of drugs to either kill or suppress the growth of cancer cells. These medications target rapidly dividing cancer cells throughout the body and can be given through the mouth or by vein.
Cisplatin and carboplatin are platinum-based chemotherapy agents that damage cancer cell DNA and ultimately result in the death of the cells. The cell division process is interfered with by paclitaxel and docetaxel, which further prevents the growth of cancer cells.
Chemotherapy is often paired with other treatments, such as surgery and radiation therapy, to maximise the chances of eliminating cancer cells.
Immunotherapy
Immunotherapy, which uses the body’s natural immune system to fight cancer, is an innovative advancement in the treatment of lung cancer. When lung cancer is advanced and has progressed outside of the lungs, this method is beneficial.
These drugs, such as nivolumab and pembrolizumab, increase the body’s natural immune response against the tumour by obstructing proteins that stop immune cells from identifying and attacking cancer cells. CAR-T cell therapy involves genetically modifying a patient’s T cells to better identify and eliminate cancer cells.
When other treatments may not be successful, these therapies provide hope for stability and possible recovery.
Conclusion
In conclusion, lung cancer affects a large number of people and has serious health consequences. Early symptom recognition can help with prompt diagnosis and intervention, which may enhance the effectiveness of treatment.
The causes, which include genetic predispositions, exposure to radon and other environmental factors, and tobacco smoke, emphasise the significance of prevention and focused treatments.
Patients now have hope because of medical advancements such as immunotherapy, chemotherapy, and radiation therapy, which highlight the value of personalised treatment plans.
