PathCAL Lung Cancer Management

Question 1

What would we call excision of an entire lung?

Answer 1

Resection of an entire lung is called a pneumonectomy.

As we might expect, this is more serious than a lobectomy and the mortality from the operation is higher.

Question 2

What do we measure from a non-small cell carcinoma lobectomy?

Answer 2

• Maximum dimension of tumour in centimetres= This gives an indication of the volume of the tumour, which in turn is a measure of the tumour cell mass. The bigger the tumour the more likely it is to have spread and, in general, the longer it’s been present in the patient.
• Histological type of tumour= to confirm that the biopsy was representative and that the typing of the tumour was accurate
• Lymph nodes to look for metastases
• Bronchial resection edge: to see if it’s clear of tumour
• Non-neoplastic lung to see if there’s any underlying lung disease.

Question 3

What are the principle main lines of lung cancer management?

Answer 3

Surgical resection
Radiotherapy
Chemotherapy

Question 4

When is radiotherapy or chemotherapy useful?

Answer 4

Radiotherapy is useful if it is blasted at a relatively localised area. So it’s useful for disease at an early stage.
Chemotherapy, in which drugs are administered systemically, is useful particularly in advanced, widespread disease.

Question 5

What effects does radiation have on the cell?

Answer 5

It damages the DNA, causing breaks and cross-links in the DNA strands, as well as oxidation of the bases. All this impairs the cell’s ability to divide. If the damage can’t be repaired, the cell will die by apoptosis.
The radiation may bring about the cellular damage either directly or indirectly by forming free radicals, which in turn may cause lipid peroxidation of cell membranes.

Question 6

What are the long-term effects radiation has on tissues?

Answer 6

It damages vascular endothelium, exposing collagen of the basement membrane and leading to thrombosis. This causes vascular insufficiency, which may lead to infarction or atrophy of the tissue supplied.
The ischaemic damage, together with cell death and loss of stem cells, leads to healing by fibrosis, leaving scarring of tissues.

Question 7

How does radiotherapy affect various tissues in the body?

Answer 7

• Intestine= damage to labile cells of surface mucosa
• Bone= damage to osteocytes
• Skin= damage to regenerating keratinocytes
• Lung= fibrosis in alveolar spaces
• Bone marrow= impaired haemopoiesis

Question 8

How is radiation particularly damaging to stem cells in various tissues?

Answer 8

• Bone marrow: it damages the hemopoietic cells: normoblasts, myeloblasts, megakaryocytes, leading respectively to anaemia, infection and haemorrhage.
• Intestine: it damages the mucosa, leading to diarrhoea.
• Gonads, although we’d usually protect these when radiotherapy is used therapeutically.
• Lungs: this would induce fibrosis. It’s not normally a big effect of radiotherapy, but in the context of lung cancer it’s relevant.

Question 9

What problems is radiation particularly useful in relieving?

Answer 9

• Pain.

- Compression of adjacent tissues.

Question 10

Describe how radiation is given

Answer 10

The radiation is given in what are called fractionated doses. This means that we give several batches of smaller doses, rather than giving it all at once in one large blast.
The reason this is done is, of course, to try to minimise the side effects of radiation.
The amount given is up to 40-70 Gy.

Question 11

For which aspects of lung cancer is radiotherapy particularly effective?

Answer 11

Haemoptysis
Pain due to invasion of chest wall or metastases
Obstruction of main bronchi
Brain metastases
Superior vena caval obstruction

Question 12

What are the side effects of radiation we would like to avoid?

Answer 12

Acute radiation sickness.
Low neutrophil count, with the possibility of infection: due to bone marrow damage.
Low platelet count, due to bone marrow damage, with haemorrhagic tendency or bruising.
Fatigue.
Gastrointestinal symptoms: vomiting, loss of appetite.

Question 13

What is the main line of treatment for small cell carcinoma?

Answer 13

Chemotherapy
(Limited disease: radiotherapy and chemotherapy.
Advanced disease: combination chemotherapy.)

Question 14

What is the recommended chemotherapeutic regime for small cell lung cancer?

Answer 14

The recommended regime for small cell lung cancer is usually either of the following:
-Cyclophosphamide + doxorubicin + vincristine.

• Cisplatin + etoposide.
• Platinum generally plays an important role.

Question 15

What are the side effects of chemotherapy?

Answer 15

The main ones are mainly nausea and vomiting, presumably because the drugs are toxic to the mucosa of the intestine.

Question 16

What do we call extra therapy given around the time of surgery in the hope of preventing later metastases?

Answer 16

It’s called adjuvant therapy.
The word adjuvant is from Latin: juvare, meaning to help, with the prefix ad-, implying in this case added on.
We sometimes qualify it to be more specific and talk about adjuvant chemotherapy or adjuvant radiotherapy.