Session 1 - General Overview (Updated & Accurate)

Question 1

What are three distinguishing features of cancer?

Answer 1

• Uncontrolled growth
• Invasion into adjacent tissues
• A tendency to undergo metastasis

Question 2

What is metastasis?

Answer 2

Tumour cells which spread from site of origin to non-contiguous locations via a variety of mechanisms.

Question 3

What differentiates benign from malignant tumours?

Answer 3

Benign tumours, unlike malignant tumours, do not grow uncontrollably, invade locally or metastasize.

Question 4

What is a carcinoma?

Answer 4

A cancer which arises from epithelial cells

Question 5

What is a sarcoma?

Answer 5

Arise from connective tissue such as bone, cartilage, fat, connective tissue and muscle.

Question 6

What is a lymphoma/leukaemia?

Answer 6

What is a lymphoma/leukaemia?

Question 7

What is a germ cell tumour?

Answer 7

Cancers derived from pluripotent cells, most often presenting in the testicle or the ovary.

Question 8

What is a blastoma?

Answer 8

Cancers derived from immature “precursor” cells or embryonic tissue, which are common in children.

Question 9

What are the biggest contributing factors to cancer?

Answer 9

90-95% of cancer cases due to environmental factors, with only 10% due to genetics

Question 10

Give three causes of cancer

Answer 10

• Tobacco
• Diet alcohol
• Obesity
• Lack of physical activity
• Infections
• Radiation
• Hormones
• Pollutants

Question 11

What is an environmental mutation called?

Answer 11

somatic mutation

Question 12

What is a genetic mutation?

Answer 12

Hereditary mutations

Question 13

What are local symptoms of cancer?

Answer 13

Restricted to the site of cancer

• Lumps or swellings
• Haemorrhage
• Ulceration
• Pain

Question 14

What are metastatic symptoms of cancer?

Answer 14

due to distant effects of the cancer that are not related to direct or metastatic spread.

• Weight loss (poor appetite)
• Fatigue
• Excessive sweating (night sweats)
• Anaemia (low RBC)

Question 15

Give five ways cancer can be detected

Answer 15

• Imaging
• Endoscopy
• Tissue samples – Histopathology
• Tests of blood and other samples
• Cancer Screening

Question 16

Give six ways we can treat cancer

Answer 16

• Surgery
• Radiotherapy
• Chemotherapy
• Hormone therapy
• Immunotherapy
• Gene therapy

Question 17

Give six hallmarks of cancer

Answer 17

1) Sandy – Self-sufficient
2) Beaches – Angiogenesis
3) Rectum – Resistant to anti-growth
4) Gets – Grows indefinitely
5) Invaded – invades into surrounding tissue
6) Regularly – Resists cell death

Question 18

Why don’t benign tumours grow uncontrollably?

Answer 18

Benign tumours grow slowly, and do not invade into tissues in the same was as a malignant tumour. By definition rarely grow uncontrollably.

Question 19

How does lung cancer produce ACTH in para-neoplastic syndrome?

Answer 19

Small cell lung cancer originates from neuroendocrine cells in the bronchus called feyrter cells, which can product ACTH.

Question 20

What does polygenic mean?

Answer 20

Polygenic diseases are conditions influenced by multiple genes.

Question 21

What is a blastoma?

Answer 21

A cell formed from multipotent blast cells in children.

Question 22

What kind of gene is BRCA1?

Answer 22

BRCA1 is a tumour suppressor gene, and its absence (due to mutation) can increase the likelihood of women developing breast cancer.

Question 23

Outline the stages of carcinogenesis

Answer 23

Initiation -> Promotion -> Progression

Question 24

What is initiation?

Answer 24

DNA damage caused by mutagens

Question 25

Give four examples of initiators

Answer 25

Chemicals Radiation Infections Replication errors

Question 26

What genes do mutagens target?

Answer 26

Oncogenes and Tumour Suppressor Genes

Question 27

What effect do mutagens have on tumour supressor genes and oncogenes?

Answer 27

Translocation and up-regulation of oncogenes, while inactivating the tumor supressore genes.

Question 28

What is the difference between direct acting carcinogens and procarcinogens?

Answer 28

Direct acting carcinogens bind to DNA directly, with examples including alkylating and acylating agents, along with cytotoxic drugs which encourage increased replication. Procarcinogens on the other hand require metabolism within the body before they can damage DNA – a key example being polycyclic aromatic hydrocarbons.

Question 29

Give five ways in which genes mutate

Answer 29

``` Alteration of bases • Strand break • Base oxidation • Deletion of bases • Deletion of chromosome fragments ```

Question 30

Give two ways in which genes are protected

Answer 30

repair mechanisms, such as mismatch and excision repair, and regulators such as p53.

Question 31

Name four types of promotoers, giving examples of each

Answer 31

* Chemical promoters – Phorbol esters and phenols * Hormones – Oestrogen in breast cancer * Inflammation – Chronic irritation, endoparasites and bacterial infection * Microbial Infection – Helicobacter pylori

Question 32

Give three ways in which cell signalling is important in cancer

Answer 32

* cell receptor expression goes up or down * receptors activate themselves * inhibitory proteins are downregulated

Question 33

Give an example of food causing cancer

Answer 33

, consumption of over-cooked red meat can increase levels of the carcinogen heterocyclic amine. This is caused by the combination of phenylalanine, creatine and heat in the animal muscle during the cooking process. HA is then metabolised by the liver to genotoxic metabolites.

Question 34

What is chemoprevention?

Answer 34

the prevention of cancer by the use of pharmacological agents that inhibit or reverse the process of carcinogenesis

Question 35

What is the difference between primary, secondary and tertiary patient groups in treatment?

Answer 35

primary (general pop), secondary (early stage + familial risk) and tertiary stage (increased-risk patients).

Question 36

How does aspirin prevent cancer?

Answer 36

Inhibits cox-1, preventing inflammation and thus promotion of cells.

Question 37

What does tamoxifen do?

Answer 37

Competitively competes with oestrogen at receptor level, preventing hormonal promotion of cancer

Question 38

Give a dietary chemopreventer

Answer 38

Turmeric

Question 39

How does Schistosomiasis cause bladder cancer?

Answer 39

Chronic inflammation causes by the schistome nematode may cause an increased cancer risk, by producing oxygen radicals which damage DNA of bladder cells, and also allow the formation of carcinogenic N-nitrosamines.

Question 40

Give three environmental categories of mutation

Answer 40

* Ultimate carcinogens bind to DNA & alter sequence * Ionising radiation / UV – strand breaks, cross links * DNA translocated to transcriptionally active regions

Question 41

Give four intracellular categories of mutation

Answer 41

* Misinterpretation of code * Polymerase slippage / base * Malalignment * Ineffective repair

Question 42

Give two examples of direct acting carcinogens

Answer 42

Alkylating and acylating agents - dimethylsulphate and chlorambucil Weak Carcinogens - Lymphoma and Leukaemia

Question 43

Give two examples of procarcinogens

Answer 43

Polycyclic aromatic hydrocarbons - Bezaanthracene - Benzopyrene Combustion of organic compounds