Lung tumours

Question 1

What is lung cancer?

Answer 1

Lung cancer is the uncontrolled division of epithelial cells which line the respiratory tract.

Question 2

What are the majority of lung cancers?

Answer 2

primary bronchial carcinomas. These are categorised into small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

Question 3

Epidemiology of lung tumours

Answer 3

• Lung cancer is the third most common cancer in the UK behind breast and prostate.
• Lung cancer accounts for 35,000 deaths within the UK alone, which is more than breast and colorectal cancer combined.
• Lung cancers are strongly associated with smoking.
• Slightly more common in men than women but incidence in women is increasing due to women smoking habits

Question 4

RFs for lung tumours

Answer 4

• increasing age
• smoking
• family history
• other environmental exposure

Question 5

Features of SCLC

Answer 5

• 15%of lung cancer cases
• Location: central lesion near the main bronchus
• Derived from neuroendocrine Kulchitsky cells

Question 6

Pathophysiology of SCLC

Answer 6

• Contain neurosecretory granules that can release neuroendocrine hormones. This makes SCLC responsible for multiple paraneoplastic syndromes:
  
  • SIADH → hyponatraemia
  • Ectopic ACTH→ Cushing’s syndrome
  • Lambert-Eatonmyasthenic syndrome
• Rapid growth and patients usually present in an advanced stage

Question 7

What are the different NSCLC

Answer 7

• Squamous cell carcinoma
• Adenocarcinoma
• Large cell carcinoma
• Carcinoid tumours
• Bronchoalveolar cell tumours

Question 8

Features of squamous cell carcinoma

Answer 8

• Location: central lesion
• columnarl into Squamous cells that produce keratin
• Paraneoplastic syndromes:
• Hypertrophic pulmonary osteoarthropathy: causes inflammation of the bones and joints in the wrists and ankles, and clubbing of the fingers and toes
• PTHrP→ hypercalcaemia
• history of haemoptysis and ALARM symptoms together with the cavitating lesion in the lung makes this the most likely diagnosis

Question 9

Features of adenocarcinoma

Answer 9

• Location: peripheral lesion
• Originate from mucus-secreting glandular cells
• Paraneoplastic syndromes:Hypertrophic pulmonary osteoarthropathy: causes inflammation of the bones and joints in the wrists and ankles, and clubbing of the fingers and toes
• Gynaecomastia
• MOST COMMON FORM IN NON SMOKERS

Question 10

Large cell carcinoma features

Answer 10

• Location: peripheral lesion commonly, but found throughout lungs
• Lack both glandular and squamous differentiation
• Paraneoplastic syndromes:Hypertrophic pulmonary osteoarthropathy: causes inflammation of the bones and joints in the wrists and ankles, and clubbing of the fingers and toes
• Ectopic β-HCG secretion

Question 11

Features of carcinoid tumour

Answer 11

• Rare
• From mature neuroendocrine cells
• Paraneoplastic syndrome: Carcinoid syndrome which causes the secretion of hormones, particularly serotonin, which leads to increased peristalsis and diarrhoea, and bronchoconstriction causing asthma.

Question 12

Bronchoalveolar cell tumour features

Answer 12

• Location: found throughout lungs
• Not related to smoking
• Can cause significant sputum production

Question 13

Signs of lung tumours

Answer 13

• Reduced breath sounds and a fixed monophonic wheeze may be present
• Stony dull percussion: suggests a malignant pleural effusion
• Supraclavicular or persistent cervical lymphadenopathy
• Extrapulmonary manifestations:

Question 14

Symptoms of lung tumours

Answer 14

• Persistent cough +/- haemoptysis
• Dyspnoea
• Pleuritic chest pain
• Recurrent pneumonia

Question 15

First line investigation for lung tumours

Answer 15

CXR

• Hilar enlargement
• Lung consolidation
• “Circular opacity” – a visible lesion in the lung field
• Pleural effusion – usually unilateral in cancer
• Collapse

Question 16

Whats the Gold standard investigation for lung tumours

Answer 16

CT chest with contrast:gold-standard imaging; requested if there is an abnormal CXRorpersistent symptoms with a normal CXR.

Question 17

Other than CT chest and CXR what other primary investigations are done?

Answer 17

PET-CT
Biopsy

Question 18

Other investigations to consider for lung tumours

Answer 18

• Mediastinoscopy:perform prior to surgery forNSCLCas CT does not always show mediastinal lymph node involvement
• Sputum cytology: generally only for those with central lesions that do not tolerate bronchoscopy
• Lung function tests:it is important to assess fitness for surgery, if eligible
• Brain imaging for metastasis: 10% of patients with advanced NSCLC have brain metastases
• FBC: anaemia of chronic disease and thrombocytosis may be noted

Question 19

What staging is used for lung tumours?

Answer 19

TNM

Question 20

General treatment for lung tumours

Answer 20

• Smoking cessation
• Pain management
• Endobronchial treatment with stents or debulking can be used as part of palliative treatment to relieve bronchial obstruction caused by lung cancer.

Question 21

Treatment for SCLC

Answer 21

• Surgery not usually offered as people with SCLC usually present late with advanced disease. Surgery is only appropriate for avery smallsubset of patients with early disease (T1-2a, N0, M0).
• Limited disease (confined to ipsilateral hemithorax):chemoradiotherapy with platinum-based agents, e.g. cisplatin
• Extensive disease:chemoradiotherapy with platinum-based agents, or palliative chemotherapy.

Question 22

Treatment for NSCLC

Answer 22

• Non-metastatic disease (stage I-IIIa):surgery, usually with adjuvant chemotherapy
  
  • Typically involves lobectomy or pneumonectomy. Segmentectomy or wedge resection (taking a segment or wedge of lung to remove the tumour) is also an option.
  • Removal of lymph nodes, if affected
  • Curative radical radiotherapycan be used as an alternative to surgery
• Metastatic disease (stage IIIb and above):palliative treatment with immunotherapy, chemotherapy, and radiotherapy

Question 23

What are the local obstructions in lung tumours

Answer 23

• Recurrent laryngeal nerve palsy
• Phrenic nerve palsy
• SVC obstruction
• Horners syndrome

Question 24

What is SVC obstruction caused by?

Answer 24

• caused by direct compression of the tumour on the superior vena cava.
• It presents with:
• facial swelling
• difficulty breathing
• distended veins in the neck and upper chest.
• “Pemberton’s sign” is where raising the hands over the head causes facial congestion and cyanosis.
• This is a medical emergency.
• Give oral dexmethasone IMMEDIATELY 8mg

Question 25

Horners syndrome

Answer 25

triad of partial ptosis, anhidrosis and miosis. It is caused by a Pancoast’s tumour(tumour in thepulmonary apex) pressing on thesympathetic ganglion.

Question 26

Where can lung tumours metastasise to?

Answer 26

• to hilar lymph nodes, lung pleura, heart, breasts, liver, adrenal glands, brain, and bones.
  
  • Adrenal: Addison’s disease
  • Liver: hepatomegaly
  • Bone: hypercalcaemia
  • Brain: focal neurological deficit

Question 27

Paraneoplastic syndromes that are caused by lung tumours?

Answer 27

SIADH
Cushings
Hypercalcaemia
Hypertrophic pulmonary osteoarthropathy
Limbic encephalitis
Lamber-eaton myasthenic syndrome

Question 28

What is limbic encephalitis

Answer 28

small cell lung cancer causes the immune system to make antibodies to tissues in the brain, specifically the limbic system, causing inflammation in these areas. This causes symptoms such as short term memory impairment, hallucinations, confusion and seizures. It is associated with anti-Hu antibodies.

Question 29

What is Lambert-Eaton myasthenic syndrome

Answer 29

small cell carcinoma prompts the body to produce autoantibodies which bind and destroy neurons. This leads to weakness, particularly in the proximal muscles but can also affect intraocular muscles causing diplopia (double vision), levator muscles in the eyelid causing ptosis and pharyngeal muscles causing slurred speech and dysphagia (difficulty swallowing).