1. Tumorigenesis 3

2. Most human cancers take decades to develop
ex) risk of dying from colon cancer is times higher in a 70 year old man than a 10 year old boy

3. Microenvironment
Normal cells, molecules, and blood vessels surrounding and feeding a tumor cell
Dynamic
Determines how tumor grows and spreads

4. Hypoxia As tumor grows larger, it gets further away from blood supply
lack of blood means lack of oxygen
leads to genetic instability

5. Hypoxia Lack of oxygen means cells under aerobic glycolysis
produce lactate

6. Hypoxia extracellular environment becomes acidic
cancer environment remains neutral

7. Necrosis!
Cells in hypoxic environment prone to necrosis (cell death due to injury or toxins)
necrotic tumors can indicate
fast growing cancer
chemo is working
immune system is fighting