Diagnosis

Lung cancer

Etiology

Etiology [dhs]

• Smoking (90% of lung cancer cases)

• Asbestos

• Radiation therapy (lymphoma and breast cancer)

• Exposure to carcinogens: arsenic, nickel, halogen ether, chromium, vinyl chloride, pollution

• Radon gas

• Chronic lung disease: chronic interstitial pneumonitis

Pathophysiology [dhs]

1. Chronic inflammation --> risk of dysplasia of the lung epithelium

2. Genetic mutations (MYC, BCL2, p53, EGFR, KRAS, p16) --> disrupts the cell cycle and promotes carcinogenesis

Classification [dhs]

• Small cell lung cancer (neuroendocrine origin) represents 20% of all lung cancers: characterized by rapid growth and early dissemination

• Non-small cell lung cancer (NSCLC): Squamous cell, large cell, and adenocarcinoma

Complications

• Horner syndrome

• Pancoasts syndrome

• Superior vena cava syndrome

• Paraneoplastic syndromes (ACTH, SIADH, hypercalcemia, carcinoid syndrome, Hyperaldosteronism, Lambert-Eaton myasthenic syndrome, cerebellar degeneration, Limbic encephalitis, Opsoclonus-Myoclonus, Polymyositis, Acanthosis nigricans, Dermatomyositis and Trousseau sign)

• Tumor lysis syndrome (hyperuricemia, hyperphosphatemia, hypocalcemia, and hyperkalemia --> treat with hydration, allopurinol, dialysis)

Epidemiology

Incidence per 100.000 [dhs][nbk][6fv]

Approach

• Blood test: Complete blood count, creatinine, calcium, PTH, electrolytes, serum osmolality, urine osmolality, liver function tests, LD

• Blood gas: acidosis, hypercarbia, hypoxia

• Chest X-ray: mediastinal widening, atelectasis, hilar enlargement, pleural effusion

• CT thorax

• Bone Scintigraphy

• PET-CT

• Sputum cytology

• Mediastinoscopy

• Bronchoscopy

• Thoracoscopy

• Transthoracic Needle Biopsy (CT- or fluoroscopy-guided)

• Thoracentesis

• Genetic testing: EGFR, ALK, BRAF, RET, ROS-1, NTRK 1/2/3, MET, KRAS, PD-L1

Treatment

Non-Small Cell Lung Cancer [kx3]

1. Stage IA - Surgery only

   • Lobectomy

   • Pneumonectomy

   • Wedge resection

2. Stage IB-IIIA - Surgery + adjuvant chemotherapy (cisplatin-based)

3. Stage II-IIIB - If surgically unresectable --> stereotactic radiation plus durvalumab

4. Stage IV - Chemotherapy (Cisplatin and/or pembrolizumab) and tyrosine kinase inhibitor based on genetic testing

Small Cell Lung Cancer [rto]

1. Stage Ia (T1N0):

   • Chemotherapy and radiation therapy + prophylactic cranial irradiation is the standard of care

   • Consider surgical resection only if true stage I (early stage)

2. Extensive-stage SCLC (beyond the supraclavicular areas or distant metastases):

   • Incurable --> palliative chemotherapy (Cisplatin, etoposide, irinotecan, carboplatin)

   • Immunotherapy: atezolizumab

   • Brain Metastases and spinal cord compression: corticosteroids

Differential diagnoses

Bronchitis, Carcinoid syndrome, Granuloma, Hamartoma, Horner syndrome, Hyperaldosteronism, Intrapulmonary lymph node, Myasthenia gravis, Pleural effusion, Pneumonia, Pneumothorax, Sarcoidosis, Superior vena cava syndrome, Syndrome of inappropriate antidiuretic hormone secretion, Tuberculosis