Lung adenocarcinoma
Why in News?
Lung adenocarcinoma is in the news because the Vatican announced that Pope Leo XIV was diagnosed with it after undergoing surgery at Rome’s Gemelli hospital to remove the lower lobe of his right lung.
General Overview & Definition
- Most Common Lung Cancer: It is a subtype of Non-Small Cell Lung Cancer (NSCLC) and accounts for approximately 40% of all lung cancer cases.
- Cellular Origin: It originates in the glandular cells that line the smaller airways and are responsible for secreting substances like mucus.
- Location: Unlike other lung cancers, it typically develops in the outer edges or peripheral regions of the lungs, specifically within the alveoli (air sacs).
- Growth Pattern: It generally tends to grow more slowly than other forms of lung cancer, though it has a tendency to spread (metastasize) to other organs in later stages.
Affected Demographics
- The Non-Smoker's Lung Cancer: It is the most common type of lung cancer diagnosed in people who have never smoked.
- Gender Disparity: It is disproportionately more common in women than in men.
- Younger Populations: While lung cancer typically affects older adults, adenocarcinoma is the most prevalent form found in individuals under the age of 45.
Causes and Risk Factors
- Smoking: Tobacco use remains the leading cause of lung adenocarcinoma overall, heavily affecting current or former smokers.
- Environmental Exposure: Significant risk factors include second-hand smoke, radon gas, asbestos, heavy industrial chemicals (like arsenic or nickel), and poor outdoor air quality (AQI).
- Genetics: Specific genetic alterations and mutations within tumour cells—such as EGFR, ALK, and KRAS mutations—are heavily linked to its development.
Symptoms
- Silent Early Stages: It frequently develops without any early symptoms and is often discovered incidentally during scans for unrelated health issues.
- Respiratory Signs: As it progresses, symptoms include a persistent chronic cough, coughing up blood or blood-tinged mucus, and shortness of breath.
- Systemic Signs: Patients may experience chest pain, hoarseness, unexplained weight loss, and chronic fatigue.
Diagnosis and Staging
- Histological Proof: A physical tissue biopsy (using a needle or bronchoscopy) is strictly mandatory to confirm the diagnosis and rule out lookalike conditions like Tuberculosis.
- Imaging: Screening and mapping are conducted using low-dose CT scans, MRIs, and PET CT scans for staging.
- Molecular Profiling: Pathologists routinely test the tissue for driver mutations (like EGFR or ALK) to see if the patient qualifies for advanced precision medicine.
Treatment
- Surgery: For early-stage localization, surgical removal of the affected lung tissue (such as a lobectomy) is the standard treatment and offers the highest chance of a cure.
- Targeted Therapy: Patients with specific genetic mutations can bypass traditional chemotherapy in favour of targeted drugs (like TKIs) that attack specific cancer cells.
- Immunotherapy: Newer treatments help the patient’s own immune system recognize and fight the cancer cells, significantly improving modern survival outcomes.
- Standard Therapies: Chemotherapy and radiotherapy remain essential tools, often used in combination before or after surgery.
