MCB Lecture 64 Neoplasia I

Question 0

Describe pathological and physiologic causes of hyperplasia

Answer 0

Pathological: too many growth factors, hormones
Physiological: growth of the uterus during pregnancy

Question 1

Describe pathological and physiologic causes of hypertrophy

Answer 1

Pathological: hypertension, leading to increased heart cell size and stenosis
Physiological: athletes heart, lifting weights: increased muscle size

Question 2

Describe two causes of metaplasia

Answer 2

Smoking: ciliated columnar epithelium replaced with stratified squamous
Barrett oesophagus: simple squamous replaced with columnar in response to gastric acid reflux

Question 3

What is dysplasia?

Answer 3

Pre malignant condition of proliferation

Question 4

What are the features of cells that have undergone dysplasia?

Answer 4

Loss of cell polarity
Loss of tissue architecture
Atypical mitoses
Proliferation

Question 5

What is the outcome of dysplasia?

Answer 5

Expected progression on to cancer

Question 6

What is neoplasia?

Answer 6

New growth of cells

Question 7

What is the name for the study of cancer?

Answer 7

Oncology

Question 8

What suffix is used to denote benign neoplasms?

Answer 8

-oma

Question 9

What are the features of benign neoplasms?

Answer 9

Well differentiated
Discrete location
Can not invade and replace healthy tissues
Can’t metastasise

Question 10

What is cystic teratoma?

Answer 10

This is an example of a benign neoplasm

It arises from stem cells, so many different tissue types are see that produce hair, teeth and secrete stuff

Question 11

What are the features of malignant neoplasms?

Answer 11

They can metastasise and invade and replace healthy tissues
They are no longer well differentiated
They are not localised to a discrete area
Much dysplasia
Less differentiated

Question 12

What are the most common cancers?

Answer 12

The gender specific cancers such as breast and prostate are the most common

Question 13

Which cancers contribute to the most deaths?

Answer 13

Lung, colorectal, breast and prostate

Question 14

What is an individual’s lifetime risk of cancer?

Answer 14

1/3

Question 15

What are the two broad categories of aetiology of cancer?

Answer 15

Environmental and hereditary

Question 16

What are some environmental causes of cancer?

What are the common features of the mode of action of these things?

Answer 16

Smoking, industrial, dietary

They all contain highly reactive oxygen species that make the genome unstable

Question 17

All cancer, hereditary or otherwise, is due to …

Answer 17

Genomic instability

Question 18

Why are double stranded breaks dangerous?

Answer 18

When the cell tries to repair this, mistakes are often made, leading to mutations

Question 19

What does non-ionising radiation do?

Answer 19

Makes thiamine dimers

Question 20

What does ionising radiation do?

Answer 20

Causes double and single stranded breaks

Question 21

Describe how oncogenic viruses cause cancer

eg?

Answer 21

They insert genes into the host genome. This may disrupt tumour suppressor genes

HPV, EDV

Question 22

Describe how immunodeficiency leads to cancer

Eg. ?

Answer 22

When an individual is immunosupressed, they can not kill neoplastic cells and many tumours result

E. HIV

Question 23

How can chronic inflammation lead to cancer?

Answer 23

The cytokines and other inflammatory substances are highly reactive

Question 24

How can genetics play a role in cancer?

Answer 24

Gene mutation of an oncogene or tumour suppressor gene

Eg. BRCA-1, Rb gene, APC

Question 25

What are the 5 methods of detection of cancer?

Answer 25

Physical examination
Histology / cytology
Tumour markers
Imaging 
Molecular diagnosis

Question 26

Describe how physical examination is used to detect cancer

Answer 26

This is no longer sufficient

Question 27

Describe how cytology and histology is used to detect cancer

Answer 27

Looking at biopsies under the microscope: cell numbers and tissue structure etc.

Question 28

Describe how tumour markers are used to detect cancer

What are the two main ways this is done?

Answer 28

Immunohistochemistry: using MHC that is specific for antigens involved with cancer
Eg. EGF receptor is the antigen. MHC binds, and is seen because it is marked

Biochemical assay: same thing, done in the blood

Question 29

Describe how imaging is used to detect cancer

Answer 29

Inject isotopically marked glucose and then use PET scanning to see where is highly metabolically active

Question 30

How can cancers be diagnosed molecularly:

• What are we looking for?
• How can we find it?

Answer 30

PCR: eg. Of BCR-abl to detect residual leukaemia cells in CML

Genome wide profiling: microarrays, RNA-seq

Question 31

Describe the difference in survival rate when breast cancer is detected early

Answer 31

Early detection: 98% survival over next 5 years

Question 32

What are the two modes of staging of cancer?

Which is the most useful?

Answer 32

Grading
Staging

Staging is more useful

Question 33

Describe how grading of cancer is done

Answer 33

Look at the cells and grade them based on:
Level of differentiation
Mitoses
Architecture

Give it a grade from low to high

Question 34

Describe how staging of cancer is done

Answer 34

Stage it based on: size of primary lesion T
Presence of metastasis M
Extent of spread to region lymph nodes N

Question 35

Describe the TNM system of cancer staging

Answer 35

T: size of primary tumour
M: presence of metastasis
N: extent of spread to the regional lymph nodes

Eg T1-T4