…cells that cannot control their growth rate and continue to divide without dying o This forms tumors o Cells usually invade nearby tissue and often spread to other parts of the body  Most cancers are named for the organ or type of cell where they start o e.g., cancer that begins in the colon is called colon cancer; cancer that begins in the skin is skin cancer

 Benign (NONcancerous) tumors don’t spread  Malignant tumors spread to other parts of the body and are the most dangerous, the process of spreading is called metastasis. o You might hear: “the cancer has metastasized”

 Cancer forms when there are mutations (abnormalities) in DNA  Oncogenes (genes that play a role in normal cell growth) may be mutated, causing cells to abnormally divide  p53 is a tumor suppressor gene that can be mutated -- p53 checks for mutations in DNA and fixes them or stops mitosis; when p53 is mutated, mitosis continues even though DNA is damaged

 Hereditary cancer happens when the gamete (egg or sperm) DNA is mutated  This causes all of your DNA to contain the cancer mutation, because your DNA comes solely from your parents’ gametes. o With the mutation, the risk of developing cancer is higher  Only mutations in gametes can be inherited

 Carcinogen = something known to cause cancer  Examples of common carcinogens: o Tobacco o Sunlight o X-rays o Viral infection (e.g., HPV) o Radon gas

According to some studies, nearly two out of three people can avoid cancer by… not smoking eating a low-fat diet with lots of fruits and vegetables Other habits that help prevent cancer include: Limiting alcohol use Including physical activity in your daily routine Maintaining a healthy body weight Reducing environmental exposure to carcinogens Using sunscreen when outside

 Surgery to remove the tumors (sometimes too risky)  Chemotherapy = Use of drugs as treatment o Some of them prevent mitosis o These drugs have side-effects and can affect normal cells too, so their use is limited.  Radiation Therapy = use of radiation to treat cancer cells o Uses radiation to target cancer cells and kill them o Kills cancer cells more easily but also kills some normal cells