Aetiological agents

Question 1

The carcinogens in cigarette smoke cause mutation in which gene?

Answer 1

p53 tumour suppressor gene

Question 2

Aromatic amines are associated with which cancer?

Answer 2

Bladder cancer

Question 3

Benzenes are associated with which haemotological cancer?

Answer 3

Leukaemia

Question 4

What adenocarcinoma does wood dust cause?

Answer 4

Nasal

Question 5

Vinyl chloride is associated with?

Answer 5

Angiosarcomas

Question 6

An accumulation of radioactive iodine can cause what cancer?

Answer 6

Thyroid

Question 7

Why do low fibre diets increase the incidence of colorectal cancers?

Answer 7

Decreased transmit time through the bowel, increases exposure time to carcinogenic substances found in food i.e. nitrosamines

Question 8

What category of cytotoxic drug can cause acute leukemia?

Answer 8

Topoisomerase inhibitors

Question 9

How does HPV contribute to cervical and anal cancers? (Mechanism)

Answer 9

The E6 protein produced by HPV16 binds to, and inactivates, the p53 protein. This leads to dysregulation of the cell cycle and apoptotic pathways, with subsequent malignant transformation of infection epithelial cells.

Question 10

What cancers is the epstein barr virus (EBV) associated with?

Answer 10

Non-Hodgkin’s lymphoma and other lymphomas

Question 11

What is the mechanism behind EBV’s carcinogenic properties? (Mechanism)

Answer 11

Epstein Barr Nuclear antigens cause a 14:8 translocation, in which the proto-oncogene c-myc on chromosome 8 becomes transcriptionally controlled by elements of immunoglobulin genes on chromosome 14

Question 12

How much does Hep B increase the risk of hepatocellular cancer by?

Answer 12

Greater than 100 x increased risk

Question 13

What retrovirus infection causes cancer in humans?

Answer 13

HTLV1 is associated with T-cell lymphomas

Question 14

How do retrovirus cause cancer? (Mechanism)

Answer 14

Retrovirus’ integrate themselves into the cellular genome and cause abnormal over expression of oncogenes

Question 15

Which cancer does H. Pylori cause?

Answer 15

Mucosal associated lymphoid tissue (MALT) tumours

Question 16

Why are immunosuppressed patients at more risk of certain cancers?

Answer 16

Immunosuppression damages the parts of the immune system involved in tumour surveillance, meaning the body cannot fight tumours as in a healthy person

Question 17

What are common presentations for cancer patients?

Answer 17

Lumps (breast, changes in moles, nodules, nodes)
Bleeding (haemoptysis, rectal, haematuria, post-menstrual)
Pain
Change in function (bowel habits, new cough, SOB, weight loss, fever, confused state)

Question 18

Describe tumour grades X to 3

Answer 18

X - grade of differentiation cannot be assessed
1 - well differentiated: similarities remain to normal tissue of the organ of origin
2 - moderately differentiated
3 - poorly differentiated: bizarre cells

Question 19

What does lymph node involvement indicate? (especially in which cancers)

Answer 19

Lymph node involvement is a powerful indicator of probably systemic blood borne metastases
Especially important in breast and colon cancer - if disease has extended to lymph nodes, chance of metastases is high and they need adjuvant chemotherapy