7. Respiratory Pathology

Question 1

Summarise the epidemiology of Lung Cancer?

Answer 1

• 3rd most common cause of death in the UK
• Quarter of all cancer deaths
• 80% of patients die within 1 year of diagnosis
• 5 year survival is 5.5%
• Causes - tobacco, radon, asbestos

Question 2

What is mutational compensation?

Answer 2

• House-keeping genes induce apoptosis for control
• Viral oncogenesis + smoking make these cells more proliferative
• Cells can’t be immortal

Question 3

What are the trends in smoking prevalence and mortality?

Answer 3

• Steady decline in prevalence in men
• Peak in prevalence for women was 15 years later than men
- mortality in women declining in women later than in men

Question 4

What are the clinical features of lung cancer?

Answer 4

• Haemoptysis - coughing up blood
• Chest/shoulder pain
• Dyspnoea
• Hoarseness
• Finger clubbing (nail bed >180 degrees)

Question 5

What is the first step of lung cancer classification?

Answer 5

• Non-small cell cancer

* Small cell lung cancer

Question 6

What is TNM classification?

Answer 6

• Tumour
- location of tumour
- closer to mediastinum or chest wall => higher T staging (T1a = small tumour in periphery, T4 = large tumour adjacent to big structures)
• Lymph nodes
- spread to lymph nodes in neck - higher staging (N3)
- surgery not practical if N3
• Metastasis
- M0 - hasn’t spread to another lung
- M1a - spread to another lung, lung lining or heart lining
- M1b - single area of cancers beyond regional nodes
- M1c - more than one area of cancer in one or several organs
- could lead to Superior Vena Cava obstruction

Question 7

What is a fine needle aspiration?

Answer 7

• Method to sample a few cells

* Looked at for cancerous cells by pathologists

Question 8

How does PET scan work?

Answer 8

• Used to assess spread of tumour
• Patient fasts for 4 hours, then given radiolabelled glucose
• Tumour is metabolically acitve => more glucose shows up
• Kidneys are naturally very metabolically active

Question 9

What is the diagnostic strategy for a possible lung cancer?

Answer 9

• Initial symptoms (mainly haemoptysis)
• Abnormal Chest X-Ray
• Refer to respiratory
• Pulmonary function tests/CT scan/exercise tests
• Diagnosis/staging
• Investigation (PET-CT, PFTS, MRI Brain)

Question 10

What does treatment for Small Cell Lung cancer usually involve?

Answer 10

• Removed cancer before it spreads if localised (70% 5 year survival in this particular case)
• Chemotherapy and radiotherapy is it spreads (early as possible as it grows rapidly and metastasises early)
• Palliative radiotherapy if debilitated
• Prophylactic brain radiotherapy if tumour disappears
• Aggressive treatment can kill someone who is very debilitated

Question 11

How large does a tumour have to be for a diagnosis to be made?

Answer 11

10mm

Question 12

What size is the tumour when most patients present for a check up?

Answer 12

30mm

Question 13

Put the following cancer types in order of growth from fastest to slowest:
• Squamous
• Adenocarcinoma
• Undifferentiated
• Small cell

Answer 13

• Small cell
• Undifferentiated
• Squamous
• Adenocarcinoma