Lung Cancer

Question 1

What is the biggest cause of lung cancer?

Answer 1

Smoking

Question 2

How much of lung cancer is thought to be preventable?

Answer 2

80%

Question 3

What are the two histological types of cancer and how much of cancer do they each make up?

Answer 3

Non-small cell lung cancer (around 80%):

Small cell cancer (80%)

Question 4

What are the types of non-small cell cancer?

Answer 4

Adenocarcinoma (around 40%)
Squamous cell carcinoma (around 20%)
Large-cell carcinoma (around 10%)
Other types (around 10%)

Question 5

Pathology and clinical features of:

Adenocarcinoma

Answer 5

Pathology:

Located peripherally (in the smaller airways)
Histology: glandular differentiation

Clinical features:

More common in non-smokers and Asian females
Metastasise early

Responds well to immunotherapy

Question 6

Pathology and clinical features of:

Squamous cell cancer

Answer 6

Pathology:

Located centrally (in the bronchi)
Histology: squamous differentiation (keratinisation)

Clinical features:

More common in smokers
Secrete PTHrP, causing hypercalcaemia

Metastasise late (via lymph nodes)

Question 7

Pathology and clinical features of:

Large cell carcinoma

Answer 7

Pathology:

Located peripherally and centrally
Histology: large and poorly-differentiated

Clinical features:

More common in smokers
Metastasise early

Question 8

Pathology and clinical features of:

Small cell cancer

Answer 8

Pathology:

Located centrally
Histology: poorly-differentiated

Clinical features:

More common in older smokers
Metastasise early

Secrete ACTH (Cushing’s syndrome) and ADH (SIADH)

Associated with Lambert-Eaton syndrome

Question 9

Risk factors

Answer 9

The main risk factor is tobacco smoking, which is associated with 80% of lung cancer cases.

Other important risk factors include:

Air pollution (indoor and outdoor)
Family history of cancer, especially lung cancer
Male sex
Radon gas (typically affects miners)

Question 10

Signs and symptoms

Answer 10

Shortness of breath - new onset
Cough - least 3 weeks
Haemoptysis (coughing up blood)
Chest pain - (due to the tumour invading the pleura or the chest wall)
Finger clubbing
Recurrent pneumonia
Weight loss - (>5% in 6 months)
Lymphadenopathy – often supraclavicular nodes are the first to be found on examination
Bone pain (due to metastases – commonly the spine, pelvis and long bones)9
Fatigue (due to anaemia of chronic disease)

Question 11

First line investigation

Answer 11

Chest X-ray is the first line investigation in suspected lung cancer. Findings suggesting cancer include:

Hilar enlargement
“Peripheral opacity” – a visible lesion in the lung field
Pleural effusion – usually unilateral in cancer
Collapse

Question 12

Explain other investigations

Answer 12

Staging CT scan of chest, abdomen and pelvis to establish the stage and check for lymph node involvement and metastasis.

PET-CT (positron emission tomography) They are useful in identifying areas that the cancer has spread to by showing areas of increased metabolic activity suggestive of cancer.

Bronchoscopy with endobronchial ultrasound (EBUS) This allows for detailed assessment of the tumour and ultrasound guided biopsy.

Histological diagnosis to check the type of cells in the cancer requires a biopsy. This can be either by bronchoscopy or percutaneously (through the skin).

Question 13

NICE threshold for urgent 2 week referral

Answer 13

The NICE criteria for a 2-week wait referral for lung cancer are:

Chest X-ray findings suggestive of lung cancer, or
Over 40 years old and unexplained haemoptysis

Question 14

NICE urgent CRX threshold

Answer 14

40 years old, and have two of the following unexplained symptoms (one if they have ever smoked):

Cough
Weight loss
Appetite loss
Dyspnoea
Chest pain
Fatigue

Question 15

First line treatment for non-small cell cancer

Answer 15

Surgery is offered first line in non-small cell lung cancer to patients that have disease isolated to a single area with intention to cure the cancer.

Lobectomy (removing the lung lobe containing the tumour) is first line.

Segmentectomy or wedge resection (taking a segment or wedge of lung to remove the tumour) is also an option.

Question 16

When can radiotherapy be used in non-small cell cancer?

Answer 16

Radiotherapy can also be curative in non-small cell lung cancer when early enough.

Question 17

When can chemotherapy be used in non-small cell cancer?

Answer 17

Chemotherapy can be offered in addition to surgery or radiotherapy in certain patients to improve outcomes (“adjuvant chemotherapy”) or as palliative treatment to improve survival and quality of life in later stages of non-small cell lung cancer.

Question 18

Treatment in small cell cancer

Answer 18

Treatment for small cell lung cancer is usually chemotherapy and radiotherapy. Prognosis is generally worse from small cell lung cancer than non-small cell lung cancer.

Question 19

Stage One Lung Cancer

Answer 19

One small tumour (<4cm) – localised to one lung

Question 20

Stage Two Lung Cancer

Answer 20

Larger tumour (>4cm) – may have spread to nearby lymph nodes

Question 21

Stage Three Lung Cancer

Answer 21

Tumour that has spread to contralateral lymph nodes, or grown into nearby structures (e.g. trachea)

Question 22

Stage Four Lung Cancer

Answer 22

Tumour that has spread to lymph nodes outside the chest, or other organs (e.g. liver)

Question 23

What type of cancer is worse?

Answer 23

Generally, small cell cancer is more aggressive than non-small cell lung cancer.

Question 24

What cells do lung cancers arise from?

Answer 24

Epithelial cells that line the airways.

Question 25

What is Cushing’s Syndrome?

Answer 25

Cushing’s syndrome is a disorder that occurs when your body makes too much of the hormone cortisol over a long period of time.

Question 26

What is SIADH?

Answer 26

A condition in which the body makes too much antidiuretic hormone (ADH).

Question 27

What is Lamberts -Eaton Syndrome?

Answer 27

Lambert-Eaton Syndrome is a result of antibodies produced by the immune system against small cell lung cancer cells. These antibodies also target and damage voltage-gated calcium channels sited on the presynaptic terminals in motor neurones.

Patients with Lambert-Eaton have reduced tendon reflexes. A notable finding is that these reflexes become temporarily normal for a short period following a period of strong muscle contraction. This is called post-tetanic potentiation.

In older smokers with symptoms of Lambert-Eaton syndrome consider small cell lung cancer.

Question 28

What is Mesthelioma?

Answer 28

Mesothelioma is a lung malignancy affecting the mesothelial cells of the pleura. It is strongly linked to asbestos inhalation.

There is a huge latent period between exposure to asbestos and the development of mesothelioma of up to 45 years.

The prognosis is very poor.

Chemotherapy can improve survival but it is essentially palliative.

Question 29

What are the two types of palsy associated with lung cancer?

Answer 29

Recurrent laryngeal nerve palsy presents with a hoarse voice. It is caused by the cancer pressing on or affecting the recurrent laryngeal nerve as it passes through the mediastinum.

Phrenic nerve palsy due to nerve compression causes diaphragm weakness and presents as shortness of breath.

Question 30

What complication of lung cancer is a medical emergency?

Answer 30

Superior vena cava obstruction.

It is caused by direct compression of the tumour on the superior vena cava.

It presents with facial swelling, difficulty breathing and distended veins in the neck and upper chest.

“Pemberton’s sign” is where raising the hands over the head causes facial congestion and cyanosis.