Lung Cancer Flashcards
What is the leading cause of cancer death?
Lung cancer
Lung cancer is the ____ most common cancer in the UK
3rd
What is the main risk factor for lung cancer?
Smoking
What is the peak age for lung cancer and which sex is it more common in?
75-90
Males
Is lower socioeconomic status a risk factor for lung cancer?
Duration, intensity, when they stopped
What are other aetiological factors than smoking?
Asbestos exposure (plumbers, ship-builders, carriage workers, carpenters) - risk up to 2x
Radon - e.g. silver miners in Germany late 19th century; 1950s uranium mining in Colorado
Indoor cooking fumes - wood smoke, frying fats
Chronic lung diseases (COPD, fibrosis)
Immunodeficiency
Familial/genetic - several loci identified
(Passive smoking is also a risk factor)
Describe the pathogenesis of lung cancer
May arise from any differentiated or undifferentiated cell
Interaction between inhaled carcinogens and epithelium of upper and lower airways leads to the formation of DNA adducts: pieces of DNA covalently bound to a cancer-causing chemical
Persistence/misrepair of DNA adducts may result in a mutation and can cause genomic alterations
Key if they occur in critical oncogenes and tumour suppressor genes
Name the 3 types of non-small cell lung cancer (NSCLC)
Squamous cell carcinoma
Adenocarcinoma
Large cell lung cancer
What do squamous cell carcinomas originate from?
Bronchial epithelium
Centrally located
What do adenocarcinomas originate from?
Mucus-producing glandular tissue
Peripherally located
Are large cell lung cancers differentiated?
No
Heterogeneous group
What does small cell lung cancer originate from?
Pulmonary neuroendocrine cells
How malignant is small cell lung cancer?
Highly
What is the most common type of lung cancer?
Adenocarcinoma (~40%)
(previously squamous cell carcinoma)
What is the definition of metaplasia?
Reversible change in which one adult cell type is replaced by another adult cell type; adaptive
What is dysplasia?
Abnormal pattern of growth in which some of the cellular and architectural features of malignancy are present; pre-invasive stage with intact basement membrane
Mutations in what 4 genes are important for directed treatments of lung cancer?
Epidermal growth factor receptor (EGFR) tyrosine kinase (adenocarcinomas)
Anaplastic lymphoma kinase (ALK) tyrosine kinase
c-ROS oncogene 1 (ROS1) receptor tyrosine kinase
BRAF (downstream cell-cycle signalling mediator) - especially in smokers
What are the key symptoms of lung cancer?
Cough
Breathlessness
Fatigue
Chest pain
Weight loss
Haemoptysis
Can lung cancer frequently be asymptomatic?
Yes
Why is making an initial diagnosis of lung cancer through the symptoms difficult?
The key symptoms overlap with many other respiratory diseases
Why is it important to screen for lung cancer?
The tumour can get quite large before it starts to cause issues
What are the neurological features of metastatic lung cancer?
Focal weakness - due to cardiac vegetations that embolize to main cerebral arteries
Seizures - due to chemo given via spine or when cancer reaches brain
Spinal cord compression
Why is there bone disease in lung cancer?
When lung cancer spreads to the bones, it’s calledbone metastasis
Bone metastasis can result in complications such as weakened bones and fractures, nerve damage in your spinal cord, and severe pain
What are the paraneoplastic syndromes characteristic of metastatic lung cancer?
Clubbing - result of hypoxaemia - increased blood flow to the finger area, leading to the accumulation of fluid in the soft tissues at the terminal portion of the finger and subsequent bulging of the area
Cushing’s - Small cell lung cancer canoccasionally be a source of ectopic ACTH secretion
Hypercalcaemia - dueto increased bone resorption and release of calcium from bone
Hyponatraemia - result of SIADH
What are the 4 signs of lung cancer?
Clubbing
Cachexia (body weakness and wasting) - increased breakdown and depletion of skeletal muscle proteins
Horner’s syndrome - compression of sympathetic ganglion/disrupted supply - leading to partial ptosis, miosis and facial anhidrosis
Superior vena cava obstruction (Pemberton’s sign) - cancer may be compressing SVC/spread to the lymph nodes nearby, which become swollen
What 4 general things must be confirmed in the diagnostic strategy plan for lung cancer?
Establish most likely diagnosis
Establish fitness for investigation and treatment
Confirm diagnosis - specific type of cancer if considering systemic treatment
Confirm staging