ONCOLOGY THE STUDY OF CANCER What is it? How do you get it?
What is cancer…
Loss of Normal Growth Control Normal Rate of cell growth = rate of cell death Cancer – Mutations occur in cells and they get stuck in mitosis (no interphase)
Example of Normal Growth
The Beginning of Cancerous Growth
Tumors (Neoplasms) Tumor is formed = Mass of cells dividing too quickly REMEMBER: telomerase replaces telomeres in cancer cells
Invasion and Metastasis CANCER = when tumor cells start to migrate into other tissues
Malignant versus Benign Tumors Benign Tumors = cells are localized and do not travel to other tissues = not cancer! Malignant Tumors = cells enter bloodstream and travel to new locations and start to divide there = Cancer!!
When cancer cells spread to other organs and start to grow, they take over that organ…it no longer works properly and people get very sick. Cells in this skin tumor traveled through the blood stream and infected the liver and brain. Angiogenesis = body grows more blood cells to tumor to keep cells alive – puts extra stress on heart
Biopsy Oncologist – cancer doctor Biopsy – remove some cells from tumor to view them and see if they are cancerous
Microscopic Appearance of Cancer Cells
What causes cancer…
Chemicals cause mutations in cells…
Only a few viruses that infect human cells actually cause cancer Viruses cause mutations in cells…
Bacteria causes mutations in cells…
Heredity increases an individual's susceptibility to developing cancer
Older people have more mutations accumulated in the body. This increases the chance that one of the mutations will cause cancer…
Types of Mutations… These mutations change the amino acid changes which changes the proteins that control the cell cycle
Proto oncogenes = speeds up cell cycle Proto oncogenes = speeds up cell cycle Suppressor genes = slow down cell cycle Suppressor genes = slow down cell cycle When these genes become mutated, the cell gets stuck in mitosis