7 Respiratory Pathology: Lung Cancer Flashcards
(47 cards)
Q: In terms of most common cause of death in the UK, what place is cancer? What’s mortality within 1 year of diagnosis? 5 yr survival? What needs to happen for better prognosis? How do lung cancer rates vary globally?
A: 3rd
80%
5.5%
detect early
decreasing in developed world by increasing in non
Q: Name causative factors of cancer. (5) What do lung cancer trends follow? Therefore?
A: tobacco (++ carcinogens in smoke) radiation (e.g.) radon asbestos genetic predisposition other (e.g. heavy metals)
- lung cancer trends follow smoking prevalence
- ++ health outcomes with earlier cessation of smoking
Q: What are the clinical features of cancer? (6)
A: - haemoptysis: coughing up blood
- unexplained or persistent (3+ wks): cough
- unexplained or persistent (3+ wks) chest/ shoulder pain
- ” dyspnoea
- ” hoarseness
- finger clubbing
Q: What occurs if someone is thought to have lung cancer?
A: urgent referral for a chest X ray (CXR)
Q: Clinical history: 74 yr old male; 6 month h/o weight loss, lethargy, – appetite; haemoptysis; good performance status; smoker equivalent of 70 pack yrs; no occupational risk factors; clubbing of finger nails, nicotine staining, cachexia, diminished air entry right base.
What should happen next? (7) Finally?
A: 1. CXR
2. bronchoscopy/ CT/ lymph node biopsy (take samples when do bronchoscopy); PET scan
staging TNM classification (tumour (T1-4)- location and size, 1-4; lymph nodes (N0-3), 0-3; metastases (M0-1), 0-1)
fitness
treatment
Q: What does histopathology involve? (5) Aim?
A: confirm diagnosis;
type; stage; molecular pathology; cytology; histology (biopsy/ surgical biopsy)
Q: Summarise the type of system the airways are? How wide are bronchi? bronchiole? small airways? Role of small airways? What prevents the collapse of trachea?
A: - airway conductive system (asymmetrical dichotomous branching tubular system up to 24 times)
bronchi >1mm; bronchiole <1mm; small airways <2mm (conduct to alveoli)
cartilage prevents collapse
Q: What does the gas exchange compartment contain? (4) Where do tumours occur?
A: (alveoli)
airways; alveolar parenchyma (epithelium/ interstitium); vasculature (arteries/ veins/ lymphatics); pleura
anywhere
Q: By which type of pathway do carcinomas develop? Result in? (4) Where do mutations occur? (2)
A: multistep accumulation of mutations resulting in:
o disordered growth
o loss of cell adhesion (less organised structures)
o invasion of tissue by tumour
o simulation of new vessel formation around tumours
- mutations occur in epithelial cells and stem cells
Q: What is reflected in the histology of tumours?
A: different tumour types
Q: Which cells in the lung do tumours tend to arise from? (3) What are the 2 types? How do these types differ? (2) 2 examples. What is the most common type of lung cancer?
A: epithelial, mesenchymal (soft tissue), lymphoid
- benign: do not metastasise; can cause local complications (e.g. airway obstruction); e.g. chondroma
- malignant: potential to metastasise; variable clinical behaviour; commonest: epithelial tumours->carcinomas
Q: What is the most common type of lung cancer? What percentage of all lung cancer cases does it make up? 3 subtypes? Give occurrence rate of 2 of them.
A: Non-small cell lung cancer
about85%
Squamous cell carcinoma, adenocarcinoma, and large cell carcinoma
- squamous cell carcinoma (20-40%)
- adenocarcinoma (20-40%)
Q: What is the 5 year survival rate for early stage non-small cell carcinoma? Late stage? What can some people be offered if they have early stage non-small cell carcinoma? reason?
A: early stage 1: 60% 5 yr survival
late stage: 5% 5 yr survival
20-30% have early stage tumours suitable for surgical resection
o less chemosensitive
Q: What type of pathway leads to the development of squamous cell carcinoma? What is this a subtype of? What is squamous cell carcinoma closely related to? What is a key feature that means early detection is beneficial?
A: multi-step pathway of development
Non-small cell lung cancer
closely associated with smoking
local spread, metastasise late
Q: Where does squamous cell carcinoma manifest? (traditionally and now) Explain the pathway for development. (5) What can it lead it? What type of treatment can you get? downside?
A: proximal airways- traditionally central arising from bronchial epithelium, but recent increase in peripheries (smoking changes)
- ciliated respiratory epithelium exposed to recurrent irritation
- metaplasia
- squamous epithelium (X mucous clearing) -> more unstable
- dysplasia -> ability to invade surrounding tissue
- carcinoma
- keratinisation
- may develop fatal haemorrhage with anti-angiogenic therapy
Q: In what group of people is adenocarcinoma most common? How does this vary? (3) How has incidence changed over time? Where does it manifest itself in terms of airways?
A: commonest type in non-smokers
- commoner in far east, females and non-smokers
- increasing incidence
- distal airways and alveolar epithelium; more often multicentric
Q: What is specific to adenocarcinomas? (3) When is this form of cancer curative? What is common and early? What does histology show?
What is the target for treatment?
A: atypical adenomatous hyperplasia: proliferation of atypical cells lining the alveolar walls -> ++ size -> invasive
• early resection before invasion -> curative
• commoner in far east, females and non-smokers
• extrathoracic metastases common and early
• histology shows evidence of glandular differentiation
• variety of molecular abnormalities provide targets for treatment
Q: Describe the incidence of large cell carcinoma. How has incidence changed over time? What can cause it? Describe it.
A: uncommon
• decreasing in incidence
• occupational exposure etc.
• poorly differentiated tumours of large cells
Q: What does incidence of large cell carcinoma show? reason? What is prognosis?
A: no histological evidence of glandular or squamous differentiation
• probably v. poorly differentiated adeno/ squamous cell carcinomas
• poorer prognosis (the likely course of a medical condition)
Q: Apart from non small cell lung cancer, give another type of lung cancer. What percentage of lung cancer cases does it make up? What is the rate of survival if untreated? if treated? What is the current treatment offered? why?
A: small cell carcinoma (20%)
• survival 2-4 months untreated (10-20 months with current therapy); chemoradiotherapy (very chemosensitive)
Q: What is affected with small cell carcinoma? where? Describe the differentiation of these cells. What is it closely related to?
A: small cells
• often central near bronchi
• poorly differentiated (often just nuclei)
• very close association with smoking
Q: What percentage of those with small cell carcinoma, present with advanced disease? Describe. Prognosis? What can this type of cancer lead to?
A: 80%
divide very rapidly -> often necrotic (outgrow their blood supply)- all energy is put into proliferation
poor
paraneoplastic syndromes
Q: What are paraneoplastic syndromes? Pathogenesis? (2)
A: symptoms that occur at sites distant from a tumour or its metastasis
pathogenesis remains unclear, but these symptoms may be secondary to substances secreted by the tumour or may be a result of antibodies directed against tumours that cross-react with other tissue
(systemic effect of tumour from abnormally expressed tumour cells of factors (e.g. hormones/ other factors) not normally expressed by tissue from which tumour arose)
Q: What are the local effects of lung cancer?
A: - bronchial obstruction
- invasion of local structures
- inflammation/ irritation/ invasion of pleura/ pericardium
