3- Cancer

Question 1

Describe a neoplasm

Answer 1

abnormal mass of tissue, the growth of which is virtually autonomous and exceeds that of normal tissues. The growth is uncoordinated and persists after the cessation of the stimuli that initiated the change”

Question 2

Gives examples of glandular neoplasms

Answer 2

Adenoma
–Cystadenoma
–Papilloma
–Polyp

Question 3

Give examples of stromal neoplasms

Answer 3

Fibroma
–Lipoma
–Angioma
–Leiomyoma
–Osteoma/chondroma

Question 4

Compare benign and malignant tumours

Answer 4

B:Well’ differentiated

●Usually slow growing

●Rarely invade locally-cohesive, expansile, encapsulated mass

●Seldom metastasize

M: Anaplasia - complete lack of differentiation

• Rapid turnover- ‘chemo targets’
• ‘Infiltrative’ margins, locally
• Metastasize (except 2 tumours!!)

Question 5

What are 4 mechanisms of metastasis?

Answer 5

Lymphatic e.g. breast cancers

●Haematogenous

●Body cavities (transilomic)

●Contiguous (continuous spreading )

Question 6

Describe carcinogenisis

Answer 6

Multistep process

●Malignancy acquired in a step wise fashion - ‘tumour progression’

●Accumulation of successive mutations

Question 7

Give some carcinogen examples

Answer 7

Chemicals
●Viruses
●Ionising/non-ionising radiation
●Hormones
●Bacteria, fungi, parasites
●Miscellaneous

Question 8

What are the 4 classes of regulatory gene?

Answer 8

Growth-promoting genes - Proto-oncogenes

b. Growth-inhibiting (tumour suppressor) - Anti-oncogenes
c. Genes regulating programmed cell death – Pro-apoptotic genes
d. Genes preventing mutations in the normal cell cycle - DNA repair genes

Question 9

What are the 2 basic components of tumours?

Answer 9

Parenchyma - the cancer cells that have been transformed
Stroma - tissue around the cancer cells which consists of connective tissue, blood vessels, macrophages, lymphocytes - it’s a supportive system for the cancer cells

Question 10

What is the suffix of benign tumours, and malignant tumours for parenchyma and stroma?

Answer 10

Suffix ‘oma’, carcinoma, sarcoma

Question 11

Describe relationship between age and cancer

Answer 11

In general, higher incidence > 55 years

●Certain cancers specifically affect the young e.g leukaemias, neuroblastoma, Wilm’s tumour, retinoblastoma, primary bone sarcomas

Question 12

Describe relationship between geography and cancer

Answer 12

Stomach cancer higher in Japan compared to the USA
• Colon cancer much less in Japan
• Melanoma much more common in NZ and Australia compared to Scandinavia
• Hepatocellular Carcinoma more common in Uganda - due to aflatoxin

Oesophageal cancer more common in China due to nitrates in soil

.

Question 13

Describe relationship between environment and cancer

Answer 13

UV light
●Occupational agents like asbestos, naphthyl amine and vinyl chloride, alcohol (liver cancers), smoking (lung, bladder cancer) and
●Infections notably viruses (HPV, HBV, EBV etc)

Question 14

What are the 3 forms of hereditary cancer

Answer 14

Autosomal Dominant
Inherited cancer syndromes - single mutant gene responsible e.g. retinoblastoma, FAP

●Autosomal Recessive
Inherited defective DNA repair mechanisms e.g. Xeroderma

●Unknown
Familial cancer syndromes e.g BRCA

Question 15

Give some. Examples of carcinogens

Answer 15

hydrocarbons, amines, nitrosamines, azo dyes, alkylating agents

Question 16

Give examples of oncogenic viruses

Answer 16

EBV (BL) and HPV (CC), HBV & HCV hepatic cancers

Question 17

What are oncogenes and give some examples

Answer 17

Classic example is Rb gene (13q) in genetically inherited retinoblastoma (40%)

●P53 (house-keeper of genome)

●BRCA-1 & BRCA-2 breast cancers are familial and one of these mutations present in 80% of breast cancers

Question 18

What are the 3 factors in cancer stage

Answer 18

“Size of the primary lesion
Spread to regional lymph nodes
Presence of metastases
”

Question 19

Name 4 components of a successful screening programme

Answer 19

oReliable prediction of tumourbehaviour
oTreatment available
oTarget population has enough people at risk to justify expense
oCost-effective and reliable screening tool

Question 20

Describe the cervical screening programme

Answer 20

11th commonest cancer in UK
–Most common cancer in females <35 years
–Know disease starts as cervical dysplasia (CIN)
–Detectable with relatively easy, low cost process
–All females between 25-64 eligible
–70% reduction in death’s over 30 year programme

Question 21

How are cancers diagnosed

Answer 21

Tumour markers and blood serology used to test for the presence of cancer
• Biopsy or Fine Needle Aspiration (FNA) is used to extract a bit of tissue or fluid
to test to confirm the presence of cancer
• To see if the cancer has metastasised imagine will be used:
CT MRI PET

Question 22

What are some clinical effects of tumours

Answer 22

Benign and malignant tumours both affect the host
• Anxiety about lumps and bumps
• Related to location - pressure, ulceration, infection, bleeding etc.
• Metabolic Cancer Cachexia mediated by TNF
Increased Basal Metabolic Rate (BMR) Reduced Fat
Reduced Muscle Bulk
• Paraneoplastic Syndromes
Endocrinopathies
Hypercalcaemia
Thrombotic Diathesis
Acanthosis Nigricans (brown/black, velvety hyperpigmentation of the skin - usually found in folds of the neck, groin, naval and forehead)