Non Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is a serious and potentially life-threatening condition that affects a significant number of people worldwide. As a type of lung cancer that originates in the tissues of the lung, NSCLC is distinguished from small cell lung cancer (SCLC) by its cellular characteristics and growth patterns. This article aims to provide a comprehensive overview of non-small cell lung cancer, including its definition, stages, and prognosis.

What is Non Small Cell Lung Cancer?

Non-small cell carcinoma (NSCLC) is a type of epithelial lung cancer that differs from small cell lung cancer (SCLC) in its cellular composition and behaviour. Non-small cell lung cancer includes several subtypes, such as adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, which are distinguished by the specific cell types present and their appearance under a microscope. Understanding the distinction between NSCLC and SCLC is crucial, as it impacts prognosis and NSCLC treatment options. Familiarising oneself with the characteristics of non-small cell lung cancer can help patients navigate the challenges they may encounter, particularly regarding stage 4 NSCLC prognosis.

Non-small cell lung cancer is categorised into several subtypes based on the appearance of the tumour cells under a microscope. The main non-small cell lung cancer subtypes include:

• Adenocarcinoma: This is the most common subtype of NSCLC, starting in the cells that line the alveoli (tiny air sacs) in the lungs, where oxygen enters the blood and carbon dioxide leaves it. Adenocarcinoma is found in both smokers and non-smokers and is more common in women and younger individuals.

• Squamous cell carcinoma: This type develops in the flat cells that cover the surface of the airways in the lungs. It is more commonly associated with smoking and tends to be located near the centre of the lungs, near a main airway (bronchus).

• Large cell carcinoma: The cancer cells appear larger than typical cells under the microscope. This type can occur in any part of the lung and tends to grow and spread quickly, making it harder to treat.

• Sarcomatoid carcinoma: This is a rare subtype of NSCLC that can be aggressive and difficult to treat. It often appears in any part of the lung and can have varying growth rates.

• Adenosquamous carcinoma: This is a less common subtype of NSCLC that contains elements of both adenocarcinoma and squamous cell carcinoma.

The symptoms of non-small cell lung cancer can vary depending on the stage and location of the cancer within the lungs. Common symptoms include:

• Chest pain: Individuals may experience persistent chest pain that can be sharp or dull, often worsening with deep breaths or coughing. This discomfort can indicate underlying issues in the lungs or surrounding tissues.

• Persistent cough: A cough that does not go away or worsens over time can be a significant warning sign. It may be dry or produce mucus, leading to concerns about lung health.

• Coughing up blood: Haemoptysis, or coughing up blood, is a concerning symptom that should prompt immediate medical evaluation. This can indicate irritation or damage in the respiratory tract, potentially linked to cancer.

• Fatigue: Patients may experience extreme fatigue that is not relieved by rest, impacting daily activities. This persistent tiredness can be a result of the body's energy being diverted to fight the cancer.

• Loss of appetite: A noticeable decrease in appetite can occur, often accompanied by feelings of nausea or aversion to food. This symptom can lead to further weight loss and nutritional deficiencies.

• Unintended weight loss: Unexplained weight loss can be alarming and may be an indicator of cancer progression. It often results from a combination of loss of appetite and increased metabolic demands from the disease.

• Shortness of breath: Many patients experience increasing difficulty in breathing, which may occur even at rest. This can be caused by tumour growth obstructing airways or fluid accumulation in the lungs.

• Wheezing: A wheezing sound during breathing can signal narrowed airways, which might be due to tumours or inflammation. This symptom can make breathing challenging, especially during physical activity.

• Hoarseness: Changes in voice or persistent hoarseness can result from pressure on the laryngeal nerve. This symptom may signal nearby tumour growth and should be evaluated by a doctor.

• Nail problems: Changes in the appearance of nails, such as clubbing or discolouration, can occur in response to lung cancer. These changes may reflect underlying respiratory or circulatory issues.

• Swallowing difficulty: Dysphagia, or difficulty swallowing, can arise if the tumour presses on the oesophagus or related structures. This can lead to choking hazards and nutritional complications.

The stages of non-small cell lung cancer are determined by how far the cancer has spread. There are five main stages:

• Stage 0 (carcinoma in situ): Abnormal cells are present only in the innermost lining of the airway and have not invaded deeper into the lung tissue or spread outside the lung.

• Stage 1: The cancer is small (less than 4 cm) and localised within the lung, without spreading to lymph nodes or distant parts of the body.

• Stage 2: The cancer is larger than 4 cm or has spread to nearby structures such as the diaphragm, oesophagus, or vocal cords. It may have also spread to nearby lymph nodes.

• Stage 3: The cancer has spread to lymph nodes on the same side of the chest as the primary tumour or to structures outside the lung, such as the mediastinum, heart, or oesophagus. It may have also spread to lymph nodes on the opposite side of the chest or distant parts of the body within the chest cavity.

• Stage 4: The cancer has metastasised, spreading to distant parts of the body such as the liver, bones, or brain.

While the exact cause of non-small cell lung cancer is not known, several risk factors have been identified. These include:

• Smoking: Smoking is a major risk factor for non-small cell lung cancer, with many people diagnosed having a history of smoking. The risk increases with the number of cigarettes smoked and the duration of smoking.

• Exposure to carcinogens: Exposure to certain carcinogens, such as asbestos, radon, and arsenic, can increase the risk of developing NSCLC cancer. Occupational exposure to these substances, as well as air pollution, may contribute to the development of lung cancer.

• Genetic mutations: Certain genetic mutations, like those affecting the EGFR or ALK genes, can increase the risk of developing NSCLC cancer. These mutations may be inherited or acquired over time due to various factors, such as exposure to carcinogens or ageing.

• Smoking

• Exposure to secondhand smoke

• Exposure to other carcinogens (such as asbestos, arsenic, chromium, beryllium, nickel, soot, tar, diesel exhaust, and other chemicals)

• Radon exposure

• Air pollution

• Family history

• Previous radiation therapy to the chest for other cancers

• Inherited gene changes, such as mutations in genes like CHEK2, ATM, TP53, BRCA1, EGFR, APC, and PALB2

Preventing non small cell lung carcinoma involves reducing exposure to known risk factors and adopting healthy lifestyle choices. Some of the preventative measures include:

• Avoid tobacco smoke: Quit smoking and avoid exposure to secondhand smoke. This is the most effective way to reduce the risk of non small cell lung carcinoma.

• Reduce exposure to carcinogens: Limit exposure to radon by testing your home and workplace and taking steps to reduce radon levels if necessary. Additionally, minimise exposure to occupational carcinogens by following safety guidelines and wearing protective equipment.

• Maintain a healthy diet: Eating a diet rich in fruits and vegetables may help lower the risk of NSCLC. Avoid taking beta-carotene supplements, especially if you are a smoker, as they have been linked to an increased risk of lung cancer.

• Exercise regularly: Engaging in regular physical activity can help maintain overall health and potentially reduce the risk of developing non small cell lung cancer.

Regular screenings for those at high risk can help detect non small cell lung cancer at an earlier stage, potentially improving treatment outcomes.

If a person experiences symptoms suggestive of non small cell lung cancer, such as persistent cough, chest pain, shortness of breath, or unexplained weight loss, their doctor may recommend various diagnostic tests to determine the cause. The tests may include:

• Physical examination: A thorough physical exam, including an assessment of the patient's medical history and risk factors, can provide initial insights into their condition.

• Imaging tests: Imaging tests play a crucial role in visualising lung abnormalities. Chest X-rays, CT scans, MRIs, and PET scans are commonly used to detect tumours, assess their size and location, and identify any spread to surrounding tissues.

• Sputum cytology: This test involves analysing a sample of sputum, or mucus, coughed up from the lungs. By examining the cells in the sputum, doctors can identify cancerous changes, providing valuable information about lung health.

• Tissue biopsy: To confirm a diagnosis of lung cancer, a tissue biopsy is essential. This can be performed through several methods, including bronchoscopy (inserting a camera into the airways), mediastinoscopy (sampling tissue from the chest), or a needle biopsy to extract tissue from a suspicious area.

• Thoracentesis: If fluid accumulates around the lungs (pleural effusion), thoracentesis may be performed to collect fluid for analysis. This procedure helps determine if cancer cells are present, aiding in diagnosis and treatment planning.

• Pulmonary function tests: These tests assess lung function and capacity, helping to determine the extent of lung damage and overall health. Results guide treatment options and surgical considerations, ensuring that interventions are safe and appropriate.

• Blood tests: Blood tests are increasingly used to detect biomarkers and genetic mutations associated with lung cancer. Testing for mutations such as EGFR, ALK, KRAS, and BRAF can provide critical insights into the cancer’s biology and guide targeted therapy options.

The treatment and management of non-small cell lung cancer (NSCLC) are multifaceted and depend on several factors, including the stage of the cancer, the patient's overall health, and the presence of specific genetic mutations. Some of the treatment options include:

• Surgery: For early-stage NSCLC (stages I and II), surgery is often the primary treatment option. This may involve removing the affected part of the lung through procedures such as a lobectomy, segmentectomy, or wedge resection. In some cases, removing the entire lung (pneumonectomy) may be necessary.

• Radiation therapy: Radiation therapy, which uses high-energy rays to kill cancer cells, can be employed at various stages of NSCLC treatment. It may be used as a standalone treatment or in combination with chemotherapy (chemoradiation) for patients who are not candidates for surgery or to treat cancer that has spread to lymph nodes or other areas.

• Chemotherapy: Chemotherapy involves the use of anti-cancer medicines administered intravenously or orally to kill cancer cells. It is often used for advanced stages of NSCLC and can be given before surgery (neoadjuvant chemotherapy) or after surgery (adjuvant chemotherapy).

• Targeted therapy: Targeted therapy uses medications that target specific genetic mutations in cancer cells, such as EGFR, ALK, ROS1, RET, BRAF V600E, MET, and NTRK alterations, and is usually given to patients with identified gene mutations through genetic testing.

• Immunotherapy: Immunotherapy works by activating the body's immune system to fight cancer cells and is commonly used for advanced stages of NSCLC. It can be used alone or in combination with chemotherapy or targeted therapy. Immunotherapy medicines like durvalumab may be given after chemoradiation to help maintain disease control.

• Supportive care: For advanced stages (stage IV), treatments focus on controlling symptoms and improving quality of life through palliative procedures such as external radiotherapy, internal radiotherapy (brachytherapy), laser treatment, cryotherapy, and the use of stents to keep airways or veins open.

Living with NSCLC can be challenging, but there are several ways to manage the disease and maintain a good quality of life. Here are a few points to consider:

• Regular follow-up appointments with your doctor are crucial to monitor for any signs of recurrence or metastasis.

• Managing symptoms such as pain, shortness of breath, and fatigue is important for maintaining quality of life. This can involve medications, physical therapy, and supportive care.

• Quit smoking if you haven't already, as it can improve treatment outcomes and reduce the risk of recurrence.

• Maintain a healthy lifestyle, including a balanced diet, regular exercise, and stress management techniques.

• Seek support from family, friends, or support groups to help cope with the emotional and psychological challenges of living with NSCLC.

If you experience any symptoms that concern you, such as persistent cough, chest pain, shortness of breath, unexplained weight loss, or fatigue, it's important to consult your doctor promptly. For those undergoing treatment for non-small cell lung cancer, report any new or worsening symptoms to your doctor, as they may indicate a change in your condition or a need for adjustments in your treatment plan.

• Non-small cell lung cancer (NSCLC) is a complex disease that requires a multidisciplinary approach to treatment and management.

• The prognosis and survival rates for NSCLC depend on various factors, including the stage of the cancer, the patient's overall health, and the presence of specific genetic mutations.

• Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, and immunotherapy.

• Living with NSCLC can be challenging, but with proper care, support, and a healthy lifestyle, patients can maintain a good quality of life.

• Regular check-ups and early detection are crucial for improving the prognosis and effectively managing the disease.