Cancer Basics EQ: What does cancer have to do with the cell cycle?

What is cancer? Cancer is a disease of the cell cycle. Cells divide when they are not supposed to. Develop into tumors and eventually spread to other parts of the body.

Causes Cell with damaged DNA divides repeatedly. Normal cell cycle checkpoints do not function. Caused by: –Genetics –Drug or chemical exposure (carcinogens) –Accidental mutations

Cancer Progression DNA of cell is damaged –DNA is not repaired. Cell does not die. Cell with damaged DNA multiplies. –Immune system does not kill faulty cells. Tumor forms Blood vessels carry cells to other parts of body (metastasis)

Terms to Know Benign tumor – a tumor that is not cancerous –Will not spread to other parts of body –May be removed if it presses on other organs Malignant tumor – mass of cancer cells Carcinoma in situ – early cancer that has not yet formed a tumor –Easiest type of cancer to treat Metastasis – spread of cancer to other parts of the body –Most difficult cancer to treat

Types of Cancer Any part of the body can develop cancer –Most common cancers are in organs whose cells divide rapidly –Skin cancer, leukemia, lung cancer Named for the part of the body in which it began –A liver tumor that is the result of breast cancer is still breast cancer –Each cancer spreads to other organs in a predictable sequence

Treatment Surgery – physically cutting out a tumor –Very effective before cancer metastasizes –Few side effects –If only one cell is left behind, cancer will recur

Treatment Radiation – uses waves to damage the DNA of the cancer cells so they cannot divide –Used to treat cancer that has metastasized –Also damages DNA of healthy cells –Doctors will attempt to target specific cancer sites

Treatment Chemotherapy – used drugs to inhibit the mitotic spindle so cancer cells can’t divide –Also stops mitosis in healthy cells –Side effects: nausea, anemia, hair loss, fatigue –Used when cancer has metastasized

Prognosis Depends on the type of cancer, stage, and the TNM status All cancers are easier to treat when caught early Stage IV is the most severe. Treatment at this stage usually only extends the patient’s life a few months or years.