Lung Cancer
Overview
Lung cancer is the leading cause of cancer deaths in men and women. Lung cancer can be divided into small cell and non-small cell carcinoma. Small cell lung carcinoma presents late stage and has poorer prognosis. A solitary pulmonary nodule measuring 8 mm or less can be followed radiographically. For larger lesions, a biopsy, whether bronchoscopic, percutaneous, or surgical, should be considered. Steps in management of a patient with suspected lung cancer include tissue diagnosis, staging, preoperative evaluation, and treatment with surgery, radiotherapy, or chemotherapy.
Definition
Massive haemoptysis: More than 500 mL of blood loss that is coughed up within a 24-hour period
Horner Syndrome: Symptoms are ptosis, loss of pupillary dilation (miosis), and loss of sweating on the ipsilateral side (anhidrosis) caused by compression of the superior cervical ganglion and resultant loss of sympathetic innervation.
Superior Vena Cava syndrome: Obstruction of venous drainage, usually by external compression of the SVC, leading to edema of the face, neck, and upper part of the torso often with formation of collateral veins on the upper chest.
Aetiology and Risk Factors
There are many risk factors for lung cancer. Smoking, underlying lung disease and exposure to certain chemical are the most common.
Clinical Manifestation
Small proportion of patients with lung cancer are asymptomatic when diagnosed. In these cases, a lung nodule usually is found incidentally on chest x-ray or CT. Common signs and symptoms include cough, dyspnea, chest pain, fatigue, weight loss and hemoptysis.
Most patients with hemoptysis require evaluation with bronchoscopy. Massive hemoptysis may result in death by asphyxiation.
Diagnosis
- Bronchitis
- Pneumonia
- Sarcoidosis
- Lymphoma
- Bronchiectasis
Investigations
General
- Chest X-Ray – opacity
- Spirometry – if thinking of obstructive or restrictive lung disease
- CT
Investigations for staging
- CT
- CT- Biopsy
- PET scan
- Pleural fluid aspiration
- Lung biopsy with bronchoscopy
- Endobronchial ultrasound
- Sputum MCS
Lung Carcinoma Classification
Small cell lung carcinoma (SCLC – 20%)
Non-small cell lung carcinoma ( NSCLC – 80%)
- Adenocarcinoma
- Squamous cell carcinoma
- Large cell
Staging of SCLC is limited or extensive. NSCLC uses the TNM classification for staging.
| Lung cancer characteristics | ||||
| SCLC | Adenocarcinoma | Squamous cell | Large cell | |
| Location | Central | Peripheral | Central | Peripheral |
| Cavitation | Never | Most likely | ||
| Metastases | Early | Early | Late | Late |
| Neoplastic Syndrome and Extrapulmonary manifestation | ADH, ACTH | Thrombophlebitis | PTH | Superior vena cava syndromes + hoarseness |
Treatment
Once a patient presents with symptoms or radiographic findings suggestive of lung cancer, the next steps are as follows:
- Tissue diagnosis to establish malignant diagnosis and histologic type
- Staging to determine resectability or curative potential
- Cancer treatment: surgery, radiotherapy, or chemotherapy
Complications and Prognosis
Complication
NSCLC
- Post-obstructive pneumonia/hypoxia
- Superior vena vaca syndrome
- Paraneoplastic syndromes
SCLC
- Post-obstructive pneumonia/hypoxia
- Superior vena vaca syndrome
- Paraneoplastic syndromes
- Chemothreapy induced hematological toxicity
- Radiation induced esophageal/lung injury
Prognosis
- SCLC mean survival is 3 months if untreated, 1-1.5 year if treated
- NSCLC 50% 2 year survival without spread, 10% with spread.
Paraneoplastic syndrome
Paraneoplastic syndrome are a group of syndromes where cancer cells produce peptides that mimic certain hormones. This occurs through genetic mutations within cancer cells allow them to develop new abilities and become “neuroendocrine cells”. In lung cancer common hormone like substances produced include: PTH, ACTH and ADH.
Discussion