Pathophysiology Fundamentals (3)

Question 1

What is Cancer?

Answer 1

a disease in which abnormal cells divide uncontrollably and destroy body tissue (malignant growth)

Question 2

What is neoplasia?

Answer 2

means ‘new growth’, refer to cell proliferation (increase in no. of cells) without physiological benefit e.g. moles and warts

Question 3

What is a tumour?

Answer 3

initially meant any swelling, now describes abnormal cell growths, categorised as benign (non life threatening) and malignant (life threatening)

Question 4

Carcinogenesis

Answer 4

cells become cancerous by violating basic rules:
1) unregulated cell division (cells activate cell division without signals e.g. from hormones)
2) avoiding apoptosis (cell programmed death)
3) limitless division (cells divide without limits or inhibitors)
-> thus cells grow unrestrainedly, resist monitoring, and can invade tissues and other body parts easily

Question 5

Characteristics of cancer cells

Answer 5

Cancer cells can produce and release unique proteins, some can be tumour markers
-> these markers can be similar in benign and maligant tumours
Benign Tumours:
- grow slower
- well differentiated (look like normal cells, have mature structures and function)
- are encapsulated
Malignant Tumours:
- grow rapidly
poorly differentiated (look abnormal, less mature)
not encapsulated
-tend to invade local tissue
-malignant cells can do metaplasia (go from one cell type to another cell type)

Question 6

Distinctive cancer cell features

Answer 6

genomic instability (more mutations, avoid mechanisms of using damaged DNA), tumour-promoting inflammation, sustained proliferative signaling (abnormal cancer cell increase as they can divide and replicate without signals)
evading growth suppressors, resisting apoptosis, replicative immortality (cancer cells bypass the limits of cell replication)
Angiogenesis induction (formation of new blood vessels in the context of supporting tumour growth)
invasion and metastasis activation (formation of cancer cells in a different area to the primary cancer site)
deregulated cellular energetics (more nutrients needed)
ability to avoid immune destruction

Question 7

Causes of Cancer

Answer 7

malfunction of genes that control cell growth and division
–> due to interactions and influences of viruses, carcionogens (substance, organism, or agent capable of causing cancer), genetics, diet, immune system, hormones
5% of cancer strongly hereditary
immunosurvelliance -> immune system continues to destroy emerging cancer cells. if this mechanism is disrupted, it can lead to cancer cell overproduction and tumour formation