1. SNC 2D
Cancer

2. Minds on – what do you already know?
Cancer
What is it?
Treatment
Types
Causes
Prevention

3. Cancer Cells divide out of control
Do not respond to inhibitory signals which stop cell growth
Hereditary
Genetic predisposition to a type of cancer, runs in families
Example _______________________
Environmental
Triggered by environmental factors
“carcinogens”
Example _________________________

4. Causes Damage to DNA or mutation
Damage happens in part of DNA that codes for cell cycle
Uncontrolled cell division sometimes leads to formation or lump of cells called a tumour. This mass of cells divides with no benefit to the body.

5. Tumours Tumour cells are like healthy cells
They need nutrients and oxygen to survive and go through the cell cycle.
They need access to a blood supply…..

6. Tumours take over
The send out chemical signals to normal cells in the surrounding area
These healthy cells respond by encouraging nearby blood vessels to expand into tumour mass

7. Detecting Cancer Difficulty Rate of Growth – doubling times
The appearance of cancer (when the mass of cells is detectable) occurs long after cells start to irregularly grow and develop.
The appearance of symptoms depends on how fast the cancer cells are dividing
Rate of Growth – doubling times
Measured in doubling times
One doubling time is the time it takes for cancer cells to double in number
Varies from 10 days to several years
Average doubling time for a cancer is 4 months

8. Tumours Tumour Uncontrolled growth of cells create a mass
Benign tumour
Cells of a tumour that stay together and have no affect on surrounding tissues
Becomes disruptive when it crowds nearby cells and tissues affecting normal function

9. Tumours Malignant tumour Metastasis
Interferes with functioning of neighboring cells and tissues such as enyme or hormone production
In some cases can destroy surrounding tissues
Metastasis
When cells break away from original tumour and move to different parts of body
This is the process by which cancer can move from one part of the body to another

10. Types of Tumours

11. Calculating cancer growth
If it takes 30 doubling times for a cancer to form a tumour that is large enough to be felt through the skin with hands. Calculate
How many months
How many cancer cells
it would take to form a tumour that can be felt if the doubling time is 2 months.
# Doubling times (n)
Months (n x 2)
# cancer cells (2n) 1 2 3 30

12. Causes of cancer Genetic interitance
Some breast cancers and colon cancer
Environmental factors – Carcinogen
Promotes mutation
Lifestyle
Example _______________________________
Radiation exposure
_______________________________________
Viruses