Do Now What is cancer? What are some different types of cancer? What causes cancer?

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

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

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

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

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

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

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.

What happens after transformation? 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. 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.

Tumors Benign 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 –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.

Types of Cancer Take out your cancer research. Lets talk about what you found.