cancer

Question 1

what is carcinogenesis?

Answer 1

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

Question 2

what is a neoplasm?

Answer 2

A lesion resulting from the autonomous or relatively autonomous abnormal
growth of cells which persists after the initiating stimulus has been removed - a
new growth

Question 3

what is a tumour?

Answer 3

any abnormal swelling

Question 4

what is a benign neoplasm?

Answer 4

• localised
• slo growth rate
• non-invasive
• well-differentiated

Question 5

how can benign tumours still cause morbidity and mortality?

Answer 5

• pressure on adjacent structures
• obstruction to the flow of fluid
• production of a hormone
• transformation into a malignant neoplasm

Question 6

what are malignant neoplasms?

Answer 6

• invasive
• rapidly growing
• irregular border
• do not resemble parent cell
• poorly differentiated
• hyperchromatic nuclei

Question 7

how are malignant neoplasms graded?

Answer 7

• Well differentiated - Grade 1
• Moderately differentiated - Grade 2
• Poorly differentiated - Grade 3

Question 8

what is carcinomatosis?

Answer 8

when the patient has widespread metastases

Question 9

what is an anaplastic tumour?

Answer 9

where the cell-type of origin of a malignant neoplasm is unknown/ cannot be identified

Question 10

what is the structure of a neoplasm?

Answer 10

• Consists of neoplastic cells surrounded by a stroma

* Stroma provides mechanical and nutritional support to the neoplastic cells

Question 11

why do malignant neoplasms contain a central necrosis?

Answer 11

outgrows blood supply (rate of growth is greater than rate of angiogenesis, so causes cells at centre of neoplasia to necrose)

Question 12

what are the 2 types of benign epithelial neoplasm?

Answer 12

• Papilloma- benign tumour of non-glandular, non-secretory epithelium
• Adenoma- benign tumour of glandular/ secretory epithelium

Question 13

what are the 2 types of malignant epithelial neoplasm?

Answer 13

• Carcinoma- malignant tumour of epithelial cells

- Adenocarcinoma- carcinomas of glandular epithelium

Question 14

what is a lipoma?

Answer 14

benign tumour of lipocytes of adipose tissue

Question 15

what is a rhabdomyosarcoma?

Answer 15

malignant tumour of striated muscle

Question 16

what is a leiomyoma?

Answer 16

benign tumour of smooth muscle cells

Question 17

what is an angiosarcoma?

Answer 17

malignant tumour of blood vessels

Question 18

what malignant tumours do not follow the normal nomenclature?

Answer 18

• Melanoma (malignant neoplasm of melanocytes)
• Mesothelioma (malignant neoplasm of mesothelial cells)
• Lymphoma (malignant neoplasm of lymphoid cells)

Question 19

what are teratomas?

Answer 19

• Neoplasm formed of all 3 germ cell layers- ectoderm, mesoderm, endoderm
• Tumour may contain teeth/ hair on appearance and then histologically contain various types of epithelium

Question 20

what are blastomas?

Answer 20

tumours that resemble the embryonic form of the organ from which they arise

Question 21

what are the problems with identifying carcinogens?

Answer 21

latent interval may be decades (may forget over time- i.e. forget what you were exposed to months/ years back), complexity of environment (lots of different chemicals present in each environment), ethical constraints

Question 22

what is the process of metastasis?

Answer 22

1. Detachment of tumour cells from their neighbours
2. Invasion of surrounding extracellular matrix and connective tissue to reach conduits for metastasis (blood vessels and lymphatics)
3. Intravasation into the lumen of vessels
4. Evasion of host defence mechanisms- via aggregation with platelets, shedding of surface antigens and adhesion to other tumour cells
5. Adherence to endothelium at a remote location
6. Extravasation of cells from the vessel lumen into the surrounding tissue
7. Growth at metastatic site
8. Angiogenesis- angiogenesis promoters- vascular endothelial growth factor, basic fibroblast growth factor. Angiogenesis inhibitors- angiostatin, endostatin, vasculostatin

Question 23

give some examples of screening programmes

Answer 23

cervical, breast and colorectal cancer

Question 24

what are the 3 routes of metastasis?

Answer 24

haematogenous, transcoelomic, lymphatic