Do Now What is cancer? What are some different types of cancer? What causes cancer? Do you know anyone who has suffered from cancer?

Objectives To understand how cancer forms. To compare and contrast benign and malignant tumors. Explain the different categories of cancer.

Cancer cells begin as normal cells that become mutated in a process called “transformation”. When cell division goes wrong. 

Transformation Transformation is caused by mutations. Mutations can result from a variety of different “carcinogens” (things that cause cancer). Carcinogens can “trigger” a mutation.

Carcinogens Tobacco “Dip” : contains 28 known carcinogens. Cigarettes

Carcinogens UV Light Always wear sunscreen! Causes skin cancer (most common type of cancer) Tanning beds linked to “melanoma”- deadliest type of skin cancer. Always wear sunscreen!

Carcinogens Pesticides Overexposure has been known to cause leukemia and lymphoma.

Hereditary Some cancers are inherited through mutated genes that “turn on” the cancer.

What happens after transformation? Cancer cells divide and create new cancer cells… Usually our bodies can get rid of unwanted cells, but sometimes they fail to destroy them. Cells usually get rid of bad cells through apoptosis (cell death).

When we need more cells for reasons we discussed in class, we have genes called “proto-oncogenes” that cause our cells to divide. When we have enough cells, we have other genes called “tumor suppressing genes” that stop our cells from dividing. Oncogene: Gene that can cause cancer They work together to regulate cell growth!

Rapid Growth Cells have “density-dependent inhibition”, once an area is filled, they stop dividing. In cancer cells, they keep going and cause tumors. Cancer has no boundaries

Tumors Benign tumor Malignant tumor Abnormally growing mass of cells Can disrupt certain organs, ex: brain, if they get too big Can be completely removed with surgery Malignant tumor Spreads into neighboring tissues Can metastasize, enter blood and lymph vessels, and spread to other organs and parts of the body

Categories of Cancer Carcinomas Sarcomas Leukemias and lymphomas Originates in external or internal “coverings” such as skin or the lining of the intestine Sarcomas In tissues that support the body such as bone and muscle Leukemias and lymphomas In blood-forming tissues such as bone marrow, spleen, and lymph nodes.