Respiratory pathology - Lung cancer Flashcards
Describe the epidemiology of lung cancer?
- Third most common cause of death in UK
- 1/4 of cancer deaths
- 5 year survival is 5.5%
What are some causes of lung cancer?
- tobacco
- asbestos
- radon
What is the trend in smoking and how is it associated with mortality from lung cancer?
- Steady decline in smoking prevalence among men over the years
- The peak prevalence for women was about 15 years later
- Mirrors the mortality of lung cancer
- Mortality in men is declining over time
What are some clinical features of lung cancer?
MANY HAVE NO SYMPTOMS
unexplained/persistant for over 3 weeks:
- cough
- shoulder/chest pain
- dyspnoea
- hoarseness
- finger clubbing - greater than 180 degrees
HAEMOPTYSIS - coughing blood
What is done it if a patients presents with symptoms which could be due to lung cancer?
- X ray referral - URGENT
- If it shows a mass then a biopsy is taken
How are tumours typed and staged?
- Small cell or non small cell?
- Tumour, nodes and metasteses (e.g. T1a - letters for each of 3 parts)
What factors are considered in order to stage a tumour?
- Location of tumour indicated
- If closer to mediastinum/ chest wall/ spreads to lymph nodes in neck, has higher T staging
- Surgery impractical if spreads to lymph nodes
- Location, size and proximity to other organs
- Has it spread to other places
How are PET scans done?
- Patients have to fast for 4 hours
- Given radioactive glucose
- Tumour much more metabolically active
How is metastasis identified?
- Looking at scans, MRI, CT
What are the stages involved in lung cancer diagnosis?
- Scan
- Biopsy
- Benign/Malignant
- Type?
- Staging
- Functional capacity of person
- Prognosis
What is a trans-thoracic CT biopsy, advantages/disadvantages?
- Using CT guidance through thorax
- real time, sensitive
- risk of pneumothorax, small sample size, in case of bleeding no immediate therapy possible
Why must the patients physical condition be assessed before considering a treatment plan?
- They may have other health conditions which affect treatment
- Are they fit to undergo treatment?
What does prognosis of lung cancer depend on?
- Prognosis depends on the cell type and the extent of the spread
How can cytology be done - where and how are specimens obtained?
Cytology:
- Sputum
- Bronchial washings and brushings
- Pleural fluid
- Endoscopic fine needle biopsy of tumour/lymph nodes
How are biopsies obtained for histology (looking at tissues)?
Histology:
- Biopsy at bronchoscopy - central tumours
- Percutaneous CT guided biopsy - peripheral tumours
- Mediastinoscopy and lymph node biopsy - for staging
- Open biopsy at time of surgery