1. What is cancer? Is it contagious?

2. What is It? Proto-oncogenes: genes that start cell division
Oncogenes: “cancer genes”, caused by mutations in Proto-oncogenes, cause cells to divide constantly
Tumor Suppressors: stop cell division, if mutated they won’t stop it
Then Cancer is a group of cells that “forgot” how to stop dividing

3. Tumors Tumors: a large mass of rapidly dividing cells Types of Tumors:
Benign: cannot spread to form new tumors
Malignant (cancerous): able to spread to other tissues
Metastasis: the spreading of tumors
Tumors take away blood supply and nutrients from normal cells and interfere with normal cell functions

4. Causes of Cancer
Age
Radiation: UV light, x-rays, radioactive substances
Carcinogens: chemicals that mutate DNA
Gasoline, tobacco smoke, tobacco (chewed)
Viruses: ex: Hepatitis = #1 cause of liver cancer
Heredity
Alcohol
Obesity

5. Protection from Cancer
Avoid the above
Keep immune system strong (exercise, sleep, avoid stress, eat right)
Don’t drink, don’t smoke (secondhand included)
Don’t sunburn!

6. Cancer Treatments Surgical removal of tumors
Radiation: beams of radiation target/destroy tumors
Chemotherapy: use of drugs to treat cancer
Target/destroy fast-dividing cells

7. Question (answer in your notes)
Hair grows from hair follicles, pockets of continually dividing cells in the outer layer of the skin. New cells are added to the base of a hair shaft, inside each follicle.
Use what you have learned to explain why cancer patients often lose their hair when receiving chemotherapy and grow more hair after chemotherapy stops.