Carcinogenesis

Question 1

Define carcinogenesis

Answer 1

The transformation of normal cells to neoplastic cells through permenant genetic alterations or mutations

Question 2

What cells does carcinogenesis apply to

Answer 2

Malignant neoplasms

Question 3

Define oncogenesis

Answer 3

Benign and malignant tumours

Question 4

How many steps are in carcinogenic

Answer 4

Several

Question 5

What do carcinogens result in

Answer 5

Cancer

Question 6

What do oncogens reuslt in

Answer 6

Tumours

Question 7

What is the biggest cause of cancer

Answer 7

Environmental factors (85%)

Question 8

What are three complications with trying to identify carcinogens and risk of cancer

Answer 8

1. Can be decades to develop
2. Complexity of the environment
3. Ethical constraints

Question 9

Where is hepatocellular carcinoma common

Answer 9

AREAS with high hepatitis B/C and mycotoxins (Egypt)

Question 10

Is hepatocellular carcinoma common in UK and USA

Answer 10

No

Question 11

Where is oesophageal carcinoma common

Answer 11

Japan, China (chicken), Turkey and Iran (extremely hot coffee - repeated exposure to heat )

Question 12

What factor increases risk of oesophageal cancer

Answer 12

Food (Linhsien chickens)

Question 13

How many deaths per year is attributed to Lung Cancer

Answer 13

35,000 per year

Question 14

What factor is associated with lung cancer

Answer 14

Smoking

Question 15

What other cancer is strongly related to smoking other than lung

Answer 15

Bladder

Question 16

Where is risk of bladder cancer increased

Answer 16

Those who work in the aniline dye and rubber industries

Question 17

What is the causative agent of bladder cancer

Answer 17

Beta-nephthylamine

Question 18

Where was scortal carcinoma at its peak risk

Answer 18

Chimney sweeping

Question 19

What was the carcinogen involved in scrotal cancer with chimney sweeps

Answer 19

Polycyclic aromatic hydrocarbons

Question 20

How did chernobyl contribute to an increase in cancer incidence in Ukranian children

Answer 20

Release of I(125) and I(131) into the atmosphere

Moved into ukraine and gave children thyroid cancer 4 years later

Question 21

Name some methods of experimental evidence for cancer causes (3)

Answer 21

1. Incidence of tumours in lab animals
2. Cell/tissue cultures
3. Mutagenicity testing in bacterial cultures

Question 22

Why is experimental evidence on animals NOT an effective way to prove cancer

Answer 22

1. Animals/cultures may metabolise agents differently to humans
2. Bacterial mutation may not = carcinogenicity in bacteria but may do in humans

Question 23

What are 5 classes of carcinogen

Answer 23

1. Chemical
2. Viral
3. Ionising and non-ionising radiation
4. Hormones, parasites and mycotoxins
5. Miscellaneous

Question 24

How do chemical carcinogens act on tissues

Answer 24

1. Directly
2. Convert from pro-carcinogens -> ultimate carcinogens
3. Enzymes required may be ubiquitous or confined to certain organs

Question 25

What tumours can polycyclic aromatic hydrocarbons cause

Answer 25

Lung and Skin cancer

Question 26

What are the source of polycyclic aromatic hydrocarbons

Answer 26

Smoking | Mineral Oils

Question 27

What cancer can aromatic amines cause

Answer 27

Bladder cancer

Question 28

Source of aromatic amines

Answer 28

Rubber/dye workers

Question 29

What can nitrosamines cause

Answer 29

Gut Cancer

Question 30

What cancer can alkylating agents cause

Answer 30

Leukaemia

Question 31

What complications can arise from exposure to UV light

Answer 31

Increase in BCC, melanoma and SCC Increase in Xeroderma Pigmentosum

Question 32

In what job are skin cancers common

Answer 32

Radiographers

Question 33

What career has an increased risk of lung cancer

Answer 33

Uranium miners

Question 34

An increase in what hormone increases the chance of which cancer

Answer 34

1. Oestrogen | 2. Hepatocellular carcinoma

Question 35

What mycotoxin increases the risk of cancer and what cancer is this

Answer 35

1. Alfatoxin B1 Hepatocellular carcinoma

Question 36

What parasite increases the chance of bladder cancer

Answer 36

Shistosoma

Question 37

What parasite causes cholangiocarcinoma

Answer 37

Chlonorchis Sinensis

Question 38

What cancer is caused by Asbestos

Answer 38

Malignant mesothelioma Lung cancer Asbestosis

Question 39

What is malignant mesothelioma

Answer 39

Cancer of mesothelium

Question 40

What five host factors can result in a cancer

Answer 40

1. race 2. diet 3. constitutional factors (age, gender) 4. Premalignant lesions 5. Transplacental exposure

Question 41

What cancer is common in India and SE asia and why

Answer 41

Increased oral cancer Due to reverse smoking and metal chewing

Question 42

Why is skin cancer risk lower in blacks

Answer 42

Due to melanin

Question 43

Give three examples of constitutional host factors

Answer 43

1. Inherited predisposition 2. Age 3. Gender

Question 44

What chromosome causes increased predisposition for familial polyposis coli

Answer 44

Chromosome 5

Question 45

What chromosome causes increased predisposition for retinoblastoma

Answer 45

Chromosome 13

Question 46

How is age associated with cancer

Answer 46

Increases with age

Question 47

How is gender associated with cancer

Answer 47

e.g. Breast cancer in females

Question 48

What are premalignant lesions

Answer 48

An identifiable local abnormality that is associated with an increased risk of a malignant tumour developing at the site

Question 49

4 examples of premalignant lesions

Answer 49

1. Colonic polyps 2. Cervical dysplasia 3. Ulcerative colitis 4. Undescended testis

Question 50

How did diethylstilbestrol effect women who wanted to stop abortions

Answer 50

Increased risk of transplacental carcinogenesis