CancerCancer- abnormally growing and dividing

cells of a malignant neoplasm.

Neoplasms- abnormal masses of cells that has lost control over how they grow and divide

Benign tumor Malignant tumor

Figure 7.15aPage 109

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Cancer cells have 4 characteristics

• Grow and divide abnormally

• Cells have significantly altered cytoplasm and plasma membranes

• Cells have a weakened capacity for adhesion

• Usually have lethal effects

Cancer rates rose in most industrial nations in the 20th century

• 2nd leading cause of death in U.S.• A.C.S. estimates ½ of males and 1/3 of

females will have some form of cancer in their lifetime.

• EPA estimates that in the U.S. more than 200 million people live in areas where the combined upper limit lifetime cancer risk is 10 times the risk normally considered acceptable.

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Where does cancer come from?

• Cancer cells are not foreign cells• How does this damage occur?

– Inherited• Some forms of cancer can be hereditary,

– Viruses– HIV patients may get the cancer Kaposi sarcoma

– Carcinogens- substances that cause cancer, invasive out-of-control cell growth

– Ex: Asbestos, Benzene, DDT, Radon, PCB (all found in your neighborhood!)

– Cigarette smoke contains benzopropene, a known carcinogen.

Treating Cancer

• Surgery– By completely removing the cancerous cells, a

person can rid themselves of the cancer.

• Chemotherapy– Colchicine inhibits the development of spindles as

the nuclei are dividing.

• Radiation – Destroys the cancer cells in the treated area.

Control cell:Normal spindle forms

HTPH2 treated:Spindle formation blocked