Carcinogenesis

Question 1

What is carcinogenesis?

Answer 1

A multi-step process resulting from the accumulation of errors in vital regulatory pathways

Question 2

Tumour growth:

Define the following:

• Hypertrophy
• Hyperplasia
• Metaplasia
• Dysplasia

Answer 2

Hypertrophy - increase cell size

Hyperplasia - increase number of cells

Metaplasia - replacement of one fully differentiated tissue by another - may be a response to injury

Dysplasia - architectural and cytological changes seen in malignancy - pre-cancerous

Question 3

Aetiology of carcinogenesis:

What is the biggest chemical carcinogen?

(1) Chemical carcinogens - What are the 3 steps of their Carcinogenesis?
(2) Asbestos - Mesothelioma

(3) Radiation - X-ray:
- What type of UV light contributes most to skin cancer?

(4) Infections:

Cancers caused by:

• HiV
• H. pylori
• Schistosoma

(5) Hormones:
- Type of hormones?
- What are some risk factors of breast cancer?
- Risks of ovarian cancer?

Answer 3

Cigarette smoke

Initiation - damage to DNA/mutation 
Promotion - selective growth advantage 
Progression - irreversible and multiple complex DNA changes 
======
UV B 
======

Kaposi sarcoma

Gastric cancer and GASTRIC LYMPHOMA

Bladder cancer

======
COCP + HRT

Long term oestrogen exposure
Low parity -
Early menarche
Late menopause

Linked to the number of ovulations - nulliparity