Neoplasms

Question 1

Define neoplasm.

Answer 1

mass/tumour that is the result of neoplasia, not necessarily cancer, but that doesn’t mean it isn’t problematic

Question 2

Define neoplasia.

Answer 2

process of abnormal cell growth and differentiation, results in a mass/tumour

Question 3

What does benign mean?

Answer 3

• abnormal growth that is not malignant
• growth is uncontrolled but slow, may stop or regress
• cells are differentiated to some degree
• tumour is non-invasive

Question 4

What does malignant mean?

Answer 4

• abnormal growth that is disorderly, rapid
• results in poorly differentiated cells (anaplasia)
• doesn’t stop, keeps growing, is invasive

Question 5

What is cancer?

Answer 5

malignant tumour

Question 6

What does the word carcinoma usually mean?

Answer 6

usually denotes a malignant tumour originating in epithelial tissue

ex. adenocarcinoma = malignancy in glandular epithelium

Question 7

What does the word sarcoma usually mean?

Answer 7

usually denotes malignant tumour originating in mesenchyme

Question 8

What does “oma” usually mean?

Answer 8

usually denotes a benign tumour

ex. osteoma = benign tumour in bone

Question 9

What is the most frequently mutated gene in cancer? What does the gene normally code for?

Answer 9

TP53 gene, normally codes for a protein responsible for apoptosis, triggers cell death when DNA is damaged

Question 10

What other three groups of genes can cause cancer if they are mutated? What do the proteins they code for normally do?

Answer 10

1) DNA repair genes - reads DNA code, looks for and fixes errors
2) proto-oncogenes - “go genes” proteins tell cells to divide, enhances cell division
3) tumour suppressor genes - proteins to stop cell division and growth

Question 11

What is an oncogene?

Answer 11

Any gene that causes malignant growth.

Question 12

How long does it normally take for a malignant tumour to be detected clinically? How big does the tumour have to be to be detected clinically?

Answer 12

10 years, 1 cm

Question 13

How long does it take tumours to double in size?

Answer 13

100 days

Question 14

What are the three ways cancers spread? Explain each.

Answer 14

1) extension and invasion - tumour grows, invades surrounding tissues, damages tissue to make room for self
2) seeding - piece of tumour breaks off, no longer local, normally occurs in body cavities
3) metastasis - cancer spreads distally via blood or lymph

Question 15

What are two requirements needed for cancer to establish at a secondary site?

Answer 15

must be large and well-perfused

Question 16

What are the most common secondary sites for cancer?

Answer 16

lymphatic tissue, liver, lungs, bones, brain

Question 17

Explain the 3 stages of metastasis.

Answer 17

stage 1
- invades local tissue, uses enzymes to destroy adjacent tissue and make room for self
- eventually growing cells make contact with blood or lymph and get in
- embolus (group of malignant cells) eventually forms (normally broken up by turbulence)
- embolus is coated in platelets, protected from body’s defenses
stage 2
- embolus travels in blood or lymph
- reaches area of resistance (capillary bed)
- determines if site suitable, using cytokines, growth hormone, begins to grow
stage 3
- form new blood vessels (angiogenesis)
- cells here are same as primary site

Question 18

How can you tell a primary site from a secondary site?

Answer 18

primary site is usually one growth, secondary site usually has multiple growths

Question 19

How are tumours staged?

Answer 19

TNM system

T = size, T0 for no tumour up to 4
N = nodular involvement, not number of nodes, 0-3
M = metastasis? yes or no 0, 1

Question 20

How are tumours graded?

Answer 20

• histology is studied in the lab
• subjective determination made of tumour’s progression
• scored I to IV meaning restrictive to extensive
• refers to progress locally

Question 21

List and briefly explain six ways cancer can be treated.

Answer 21

1) radiation - high dose of radiation, generates free radicals that cause necrosis of cancer cells and healthy cells in area
2) chemotherapy - targets cell division and prevents/slows growth of cells, also targets malignant and healthy cells
3) surgery - minimal side effects but be sure to get it all!
4) immunotherapy - antigen used to stimulate body’s own immune response to target the malignant cells
5) hormone therapy - only works if tumour nurtured by hormones, either use an anti-hormone or provide hormone in high dose to desensitize
6) combination therapy - combination of any of the above