1. Biomedical Technology Cell Biology and Cancer Objective 2
Causes
and
Development
of Cancer

2. Warm up

3. What causes cancer? The Known Agents
Ultraviolet Radiation
Radium
Coal tar
Cigarette Smoke
Asbestoses

4. What does cancer represent?
It represents a
breakdown of the
processes that
regulate the growth
of normal cells and
tissues.

5. What happens when a person develops cancer?
Cancer cells multiply rapidly, taking up
space and nutrients from the normal
cells.

6. A once precisely regulated system of cell division goes wild !
Cancerous growth
disrupts and allows
uncontrolled
division of body
cells.

7. How exactly does cancer cause all this trouble?
First: Look at “Normal Cell Division”
Cell division rate is normally controlled by
two genes.
These genes are able to send messages from cell to cell telling them when to replicate, when to stay the same or when to die.

8. The genes regulate cell growth by activating the “cell cycle clock” found in each cell body.
Cancer gains control or disrupts this mechanism and the result is overcrowding and inadequate nutrition to support the increased cell growth.

9. The Stages of Tumor Development Tumors: A mass of cancer cells
Introducing !
The Stages of Tumor Development
Tumors: A mass of cancer cells

10. Stage 1: Mutation The first stage of cancer
The mutation starts in the genetic make up of the cells
Causes cells to start multiplying and dividing more rapidly that it normally would.

11. Stage 2: Hyperplasia Second stage of cancer development
Enlargement of a part due to an abnormal numerical increase of its cells.
Increase of number of cells leads to enlargement of tissue or organ involved.
Considered a pre-cancerous stage.

12. Stage 3: Dysplasia Abnormal cells that are not cancer
Starts to increase the size of tissue or organ

13. Stage 4: In Situ cancer (tumor)
Cancer that has remained within the original tissue where it started.
Has not started to spread to other parts or tissues surrounding it.
Early detection catches cancer in this stage

14. Stage 5: Invasive cancer (malignant)
Invades nearby tissues
Cells can shed from the primary tumor into the blood or lymph and invade other parts of the body.

15. Tumors threaten an individual’s
life when their growth disrupts
the tissues and organs needed
for survival.

16. Processing