Lung Cancer Flashcards
What is the biggest cause of lung cancer?
Smoking
How much of lung cancer is thought to be preventable?
80%
What are the two histological types of cancer and how much of cancer do they each make up?
Non-small cell lung cancer (around 80%):
Small cell cancer (80%)
What are the types of non-small cell cancer?
Adenocarcinoma (around 40%)
Squamous cell carcinoma (around 20%)
Large-cell carcinoma (around 10%)
Other types (around 10%)
Pathology and clinical features of:
Adenocarcinoma
Pathology:
Located peripherally (in the smaller airways) Histology: glandular differentiation
Clinical features:
More common in non-smokers and Asian females
Metastasise early
Responds well to immunotherapy
Pathology and clinical features of:
Squamous cell cancer
Pathology:
Located centrally (in the bronchi) Histology: squamous differentiation (keratinisation)
Clinical features:
More common in smokers
Secrete PTHrP, causing hypercalcaemia
Metastasise late (via lymph nodes)
Pathology and clinical features of:
Large cell carcinoma
Pathology:
Located peripherally and centrally
Histology: large and poorly-differentiated
Clinical features:
More common in smokers
Metastasise early
Pathology and clinical features of:
Small cell cancer
Pathology:
Located centrally
Histology: poorly-differentiated
Clinical features:
More common in older smokers
Metastasise early
Secrete ACTH (Cushing’s syndrome) and ADH (SIADH)
Associated with Lambert-Eaton syndrome
Risk factors
The main risk factor is tobacco smoking, which is associated with 80% of lung cancer cases.
Other important risk factors include:
Air pollution (indoor and outdoor)
Family history of cancer, especially lung cancer
Male sex
Radon gas (typically affects miners)
Signs and symptoms
Shortness of breath - new onset
Cough - least 3 weeks
Haemoptysis (coughing up blood)
Chest pain - (due to the tumour invading the pleura or the chest wall)
Finger clubbing
Recurrent pneumonia
Weight loss - (>5% in 6 months)
Lymphadenopathy – often supraclavicular nodes are the first to be found on examination
Bone pain (due to metastases – commonly the spine, pelvis and long bones)9
Fatigue (due to anaemia of chronic disease)
First line investigation
Chest X-ray is the first line investigation in suspected lung cancer. Findings suggesting cancer include:
Hilar enlargement
“Peripheral opacity” – a visible lesion in the lung field
Pleural effusion – usually unilateral in cancer
Collapse
Explain other investigations
Staging CT scan of chest, abdomen and pelvis to establish the stage and check for lymph node involvement and metastasis.
PET-CT (positron emission tomography) They are useful in identifying areas that the cancer has spread to by showing areas of increased metabolic activity suggestive of cancer.
Bronchoscopy with endobronchial ultrasound (EBUS) This allows for detailed assessment of the tumour and ultrasound guided biopsy.
Histological diagnosis to check the type of cells in the cancer requires a biopsy. This can be either by bronchoscopy or percutaneously (through the skin).
NICE threshold for urgent 2 week referral
The NICE criteria for a 2-week wait referral for lung cancer are:
Chest X-ray findings suggestive of lung cancer, or
Over 40 years old and unexplained haemoptysis
NICE urgent CRX threshold
40 years old, and have two of the following unexplained symptoms (one if they have ever smoked):
Cough Weight loss Appetite loss Dyspnoea Chest pain Fatigue
First line treatment for non-small cell cancer
Surgery is offered first line in non-small cell lung cancer to patients that have disease isolated to a single area with intention to cure the cancer.
Lobectomy (removing the lung lobe containing the tumour) is first line.
Segmentectomy or wedge resection (taking a segment or wedge of lung to remove the tumour) is also an option.
When can radiotherapy be used in non-small cell cancer?
Radiotherapy can also be curative in non-small cell lung cancer when early enough.
When can chemotherapy be used in non-small cell cancer?
Chemotherapy can be offered in addition to surgery or radiotherapy in certain patients to improve outcomes (“adjuvant chemotherapy”) or as palliative treatment to improve survival and quality of life in later stages of non-small cell lung cancer.
Treatment in small cell cancer
Treatment for small cell lung cancer is usually chemotherapy and radiotherapy. Prognosis is generally worse from small cell lung cancer than non-small cell lung cancer.
Stage One Lung Cancer
One small tumour (<4cm) – localised to one lung
Stage Two Lung Cancer
Larger tumour (>4cm) – may have spread to nearby lymph nodes
Stage Three Lung Cancer
Tumour that has spread to contralateral lymph nodes, or grown into nearby structures (e.g. trachea)
Stage Four Lung Cancer
Tumour that has spread to lymph nodes outside the chest, or other organs (e.g. liver)
What type of cancer is worse?
Generally, small cell cancer is more aggressive than non-small cell lung cancer.
What cells do lung cancers arise from?
Epithelial cells that line the airways.