Cancer CA explain how cancer spreads common cancers personal risk of cancer WHAT IS CANCER 2nd leading cause of death following CVD abnormal uncontrolled multiplication of cells which if left untreated every case begins as a change in a cell that allows the cell to grow can lead to death and divide when it should not Tumors cancers take the form of tumors but not all tumors are cancerous o benign non cancerous tumor mass of normal cells enclosed in a membrane prevents penetration of other tissues presents no danger unless it causes pressure and interferes with the fxn of other cells o malignant cancerous tumor can invade surrounding tissues can spread via lymph nodes and blood circulation Metastasis spread of cancer cells from one part of the body to nearby tissue or occurs because cancer cells do not stick to each other as strongly different parts of the body as normal cells primary tumor original location of cancer metastasizing process of traveling and seeding secondary tumors or metastases new locations of tumors Stages of cancer 0 early cancer present only in layer of cells where it originated I II III more extensive cancer with higher numbers indicating greater tumor size and or degree to which cancer has spread to nearby lymph nodes or organs adjacent to primary tumor IV advanced cancer that has spread to another organ Remission a period during the course of cancer in which there are no symptoms or other evidence of disease Types of cancer classified according to types of cells that give rise to them can retain some of the properties of the tissue of origin carcinomas sarcomas o epithelial o includes skin breast uterus prostate lungs GI tract o most common type o connective fibrous tissues o includes muscle bone cartilage muscle and fat membranes lymphomas o lymph system leukemias o bone marrow blood o abnormal increase in immature white blood cells CAUSES OF CANCER Role of DNA certain genes may predispose some people to cancer specific genetic mutations changes in normal makeup of gene o some are inherited o some caused by environmental agents radiation viruses chemical substances in the air when linked with causing cancer know as a carcinogen Tobacco use smoking responsible for 30 of all cancer deaths nearly 1 in 5 deaths nearly 443 000 premature deaths a year direct cause of lung bronchial larynx mouth pharynx esophagus stomach pancreas kidneys bladder and cervix Dietary factors one of most important factors in cancer prevention exposes you to potentially dangerous compounds and deprives you of protective compounds dietary fat and meat o colon stomach and prostate cancers o omega 3 fats are healthier for body alcohol fried foods o interacts with tobacco as risk factors for oral cancer o acrylamide probably carcinogen found in starch based foods french fries chips crackers also found in tobacco products fruits and vegg o contain essential nutrients that act as anticarcinogens o vit C vit E selenium carotenoids vit A help block cancer by o phytochemicals substances in plants that help protect acting as antioxidants against chronic diseases Carcinogens in the Environment some occur naturally o viruses UV radiation others are manufactured or synthethic substances o food preservatives and additives nitrates and nitrites found in processed meats combine with substances in stomach and convert to nitrosamines highly potent carcinogens salt and smoke cured foods linked to esophageal and stomach cancers o environmental and industrial pollution radon asbestos industrial chemicals metals plastics o radiation medical x rays radioactive substances UV rays full body CT scans COMMON CANCERS LUNG CANCER most common cause of cancer death o 160 000 deaths a year o about 14 of all new cancer diagnoses major risk factor tobacco smoke o leads to 30 of all cancer deaths 90 of lung cancer deaths o when combined with exposure to other carcinogens asbestos pollutants cancer risk multiples by factor of 10 o environmental tobacco smoke ETS second hand smoke even brief exposure can cause serious harm difficult to detect diagnose o sx persistent cough chest pain recurring bronchitis very vague hard to pinpoint as lung cancer sx do not usually appear until in later invasive stages only about 15 are diagnosed in an early stage diagnosed via chest xray CT scan treatment o depends on the type and stage of the cancer o early stage localized cancers can be tx with surgery o radiation and chemotherapy used in addition to surgery o phototherapy gene therapy immunotherapy vaccines being studied as hopeful future treatments survival rates o if detected early 53 of pts are alive 5 yrs post dx o overall 5 yr survival rate is only 16 COLON AND RECTAL CANCER 3rd most common cancer risk factors o age 91 of cases occur after 50 yrs of age o inherited gene mutations increased tendency to form colon polyps many cancers arise from preexisting polyps polyps small growths on wall of colon that may gradually develop into malignancies o chronic bowel inflammation type II diabetes o IBD inflammatory bowel disease Krohn s colitis o lifestyle habits excessive alcohol smoking obesity o diet rich in red meats processed foods simple sugars o decreasing risk factors include regular exercise diets rich in fruits vegg whole grains research is mixed on benefits of high fiber diets oral contraceptives hormone replacement decrease in colorectal cancer increase in risk of cancer in reproductive organs regular use of NSAIDs aspirin ibuprofen detection diagnosis o standard warning signs rectal bleeding any change in normal bowel movement w out any lifestyle changes o regular screening beginning around age of 50 earlier for people with family hx at high risk or showing suggestive symptoms o stool blood test can detect small amounts of blood in stool long before obvious bleeding would be noticed o more involved screenings sigmoidoscopy colonoscopy recommended at 5 or 10 yr intervals treatment o precancerous polyps and early stage cancers can be removed before they become malignant or spread o surgery is primary tx o radiation chemo 5 yr survival rates o 90 if detected early o 65 overall before surgery to shrink tumor after surgery to destory any remaining cancerous cells BREAST CANCER most common cancer in women o lung cancer is higher in cancer death o 1 in 8 american women will develop it during her lifetime about 227 000 are diagnosed each year o 1 in 30 will die from disease about 40 000 die from breast cancer each year risk factors