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.