Cancer

Question 1

What does chemotherapy do?

Answer 1

Works to counteract mutations by blocking the action of growth-signalling proteins:
Breast cancer drug Herceptin blocks over-reactive receptor tyrosine kinase (RTKs)
Drug Gleevec blocks a mutant signalling kinase associated with chronic myeloid leukaemia

Question 2

How does cancer affect tumour suppressor genes?

Answer 2

Tumour suppressor genes normally stop proliferation
Both copies in a cell must be mutated for uncontrolled division to occur
Some cancer-related mutations inactivate the tumour suppressor gene

Question 3

How do cancerous changes arise?

Answer 3

Series of mutations cause cells to proliferate more than immediate neighbours
As cluster of dividing cells grow over time, further mutations turn atypical hyperplasia into a cancer

Question 4

What is spreading of cancer to other tissues called and how does it occur?

Answer 4

Metastasis
Cancer cells enter the bloodstream or lymphatic system
As tumour grows it becomes more malignant and gains ability to break through boundaries
Invasive cancer cells often secrete proteases that enable them to degrade ECM of a tissue’s boundary

Question 5

What is a tumour?

Answer 5

Any kind of mass forming lesion

May be neoplastic, hamartomatous or inflammatory

Question 6

What is a neoplasm?

Answer 6

Autonomous growth of tissue which has escaped constraints on cell proliferation
They may be either benign or malignant
Cancers are malignant neoplasms

Question 7

Whats the difference between benign and malignant?

Answer 7

Benign: remains localised
Malignant: invades locally or spreads to distant sites

Question 8

What are hamartomas?

Answer 8

These are localised benign overgrowths of one or more mature cell types
They have architectural but not cytological abnormalities

Question 9

What are heterotopias?

Answer 9

Normal tissue but in the wrong place

e.g. pancreas in wall of large intestines

Question 10

How do we classify neoplasms?

Answer 10

Primary description is based on cell origins and secondary description is base on wether its benign or malignant
“-oma” means benign tumour
“-sarcoma” means malignant tumour

Question 11

What are teratomas?

Answer 11

Tumours derived from germ cells and contain certain tissue derived from all 3 germ cell layers
They may contain mature and/or immature tissue and even cancer

Question 12

What malignant tumours have the suffix “-oma”?

Answer 12

Lymphoma
Melanoma
Hepatoma
Teratoma

Question 13

What does invasion mean?

Answer 13

Invasion means direct extension into adjacent connective tissue and other structures

Question 14

How do normal cells differ in appearance to cancer cells?

Answer 14

Cancer cells have a larger, variably shaped nucleus
Cancer cells have many dividing cells and disorganised arrangement
Cancer cells vary in size and shape
Cancer cells have a loss of normal features

Question 15

What is growth pattern?

Answer 15

How the architecture of the tumour resembles there architecture of the tissue its derived from
Tumours will have less defined architectures that the tissue they’re derived from

Question 16

By what routes do tumours spread?

Answer 16

Perineural
Direct
Lymphatic
Haematogenous
Transcoelomic

Question 17

What is direct extension?

Answer 17

Associated with stromal response to tumour

Includes fibroblastic proliferation, vascular proliferation and an immune response

Question 18

What is haematogenous spread?

Answer 18

Via blood vessels

Venules and capillaries usually invaded because they have thinner walls

Question 19

What is lymphatic spread?

Answer 19

Spread via lymphatics to lymph nodes or beyond

Pattern of spread is identified with lymphatic drainage of organ in question

Question 20

What is transcoelomic spread?

Answer 20

Spread via seeding of body cavities

Most commonly peritoneal cavity and pleural cavity

Question 21

What is perineurial spread?

Answer 21

Via nerves

Question 22

How do we assess tumour spread?

Answer 22

Clinically
Radiologically
Pathologically

Question 23

How do we describe tumour spread?

Answer 23

T= tumour- size or extent of local invasion
N= nodes- number of lymph nodes involved
M= metastasis- presence of metastasis

Question 24

What is the difference between grade and stage?

Answer 24

Grade= how differentiated the tumour is
Stage= how far the tumour has spread
Stage is more important