Lung cancer: An overview

Lung cancer is one of the most prevalent and lethal forms of cancer worldwide. It is the top malignancy among the male population in Bangladesh. It is characterised by the uncontrolled growth of abnormal cells in the lungs, which can form tumors and interfere with normal respiratory function. Lung cancer is primarily classified into two main types: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), each with distinct characteristics, treatment approaches, and prognoses.

Epidemiology

Lung cancer is a significant public health issue. According to the World Health Organization, it is the leading cause of cancer-related deaths globally, accounting for approximately 1.8 million fatalities annually. The incidence of lung cancer varies by geography, with higher rates typically observed in regions with high smoking prevalence. Smoking is the most significant risk factor, responsible for about 85% of cases. Other risk factors include exposure to secondhand smoke, environmental pollution with lead, occupational hazards (such as asbestos and radon), and genetic predispositions.

Types of lung cancer

Non-Small Cell Lung Cancer (NSCLC): This is the most common type, comprising about 85% of lung cancer cases. NSCLC is further divided into subtypes, including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Each subtype has unique characteristics and may respond differently to treatment.
Small Cell Lung Cancer (SCLC): Representing about 15% of lung cancer cases, SCLC is known for its aggressive nature and rapid growth. It often metastasises quickly, making it more challenging to treat. SCLC is strongly associated with smoking and typically presents at an advanced stage.

Symptoms

The symptoms of lung cancer can vary widely and may not appear until the disease is advanced. Common symptoms include: Persistent cough, Chest pain, Shortness of breath, coughing of blood, unexplained weight loss and fatigue. These symptoms can also be indicative of other respiratory conditions, making early diagnosis difficult.

Diagnosis

Early-stage lung cancer may not present noticeable symptoms, which can lead to late diagnoses Diagnosis typically involves a combination of imaging studies (such as chest X-rays and CT scans) and followed by biopsies to confirm the presence of cancerous cells. Once a tumor is identified, staging tests are conducted by PET-CT Scan to determine the extent of the disease, which informs treatment decisions.

Treatment options

Treatment for lung cancer depends on the type, stage, and overall health of the patient. Common treatment modalities include:

Surgery: Often considered for early-stage NSCLC, surgical options may involve the removal of a portion of the lung (lobectomy) or the entire lung (pneumonectomy).
Chemotherapy: A systemic treatment that targets rapidly dividing cells, chemotherapy is often used for SCLC and advanced NSCLC. It can prolong survival and alleviate symptoms but comes with significant side effects, including fatigue, nausea, and immune suppression

Targeted Therapy and Immunotherapy: These newer treatments focus on specific genetic mutations or bolster the immune system’s ability to fight cancer. They can offer promising results with fewer side effects than traditional chemotherapy. However, they may not be suitable for all patients, and their high cost can be a barrier.
Radiation Therapy: This may be used as a primary treatment for patients unable to undergo surgery or as an adjunct to surgery or chemotherapy to eliminate remaining cancer cells
Prevention and lifestyle changes

Preventive measures are crucial in combating lung cancer. The most effective strategy is smoking cessation, as tobacco use is responsible for approximately 85% of lung cancer cases. Public health initiatives promoting smoking bans and education have shown positive results. Additionally, avoiding exposure to secondhand smoke, occupational hazards, and environmental pollutants can further reduce risk.

Lifestyle changes, such as maintaining a healthy diet rich in fruits and vegetables, regular physical activity, and managing stress, may also play a role in prevention. While these changes have clear health benefits, they may not eliminate the risk entirely, especially for those with genetic predispositions.

Conclusion

Lung cancer remains a formidable challenge in oncology, marked by high mortality rates and complex treatment needs. Ongoing research is vital to improve early detection, develop innovative therapies, and enhance the quality of life for patients. Public health initiatives aimed at reducing smoking prevalence and increasing awareness about lung cancer risk factors are essential in combating this disease. Early intervention and personalised treatment strategies hold promise for improving outcomes for those affected by lung cancer.