Chapter 16

 Leading cause of disease-related death among people under age 75  Second leading cause of death  Evidence supports that most cancers could be prevented by simple lifestyle changes  Tobacco is responsible for about 30% of all cancer deaths  Poor diet and exercise habits account for another 30% of cancer deaths 2

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 Definition: An abnormal and uncontrolled growth of cells that can lead to death  Tumor: A mass of tissue that serves no physiological purpose  Benign tumor: Mass of cells enclosed in a membrane that prevents their penetration of other tissues  Malignant tumor: Can invade surrounding tissues  Every case of cancer begins as: a genetic change in a cell that allows it to grow and divide when it should not 4

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 Definition: The spread of cancer cells from one part of the body to another  Primary tumor: original location of cancer  Secondary tumors (metastases) : New tumors 6

StageDescription 0Early cancer, present only where it originated IMore extensive IIGreater tumor size IIICancer has spread to nearby lymph nodes/adjacent organs IVAdvanced cancer; spread to other organs

 Classified according to types of cells that give rise to them  Carcinomas –  Sarcomas –  Lymphomas-  Leukemias - 8

 American Cancer Society Estimates:  5-year survival rate for all cancers diagnosed between 1995 and 2005 is 68% (excludes~ 1 million curable types of skin cancer)  At current rates, its estimated that1 in 2 men and 1 in 3 women will develop cancer during their lifetime 9

 American Cancer Society Estimates:  90% of skin cancer could have been prevented by protecting the skin from the sun  87% of lung cancer could have been prevented by avoiding exposure to tobacco smoke  Regular screening and self-examinations could save an additional 100,000 lives per year 10

 Most common cause of cancer related death in the U.S.  157,000 deaths  Risk factors  Tobacco smoke (including ETS) contributes to 90% of lung cancer deaths  Detection  Difficult to detect early  Symptoms do not appear until invasive stage  Symptoms: Persistent cough, chest pain, or recurring bronchitis  Diagnosis: CT scan (earlier?), chest x-ray or sputum examination, bronchoscopy 11

 Treatment  If caught early, localized cancers can be treated with surgery Only 15% detected prior to spreading so, Radiation and chemotherapy are used in addition to surgery  For cases detected early, 53% of patients are alive 5 years post-diagnosis  Overall, the 5-year survival rate is only 15% 12

 Third most common type of cancer  Risk factors  Age ( 91% of cases occur in people 50 or older)  Heredity, genetic propensity to develop polyps  Diet, smoking, excessive alcohol use and obesity 13

 Detection and treatment  Regular screening tests are recommended beginning at age 50  Symptoms: bleeding from rectum and changes in bowel habits  Treatment  Primarily Surgery  Radiation and chemotherapy can be used

 Most common cancer in women  Causes almost as many deaths in women as lung cancer  Risk factors Strong genetic factor: Age: Most common in women over 50 Early onset of menstruation First child after 30 Current use of HT Unhealthy diet and lifestyle 15

 Early detection  ACS recommends 1 mammogram/year (women over 40)  Clinical and Self breast exams (starting at age 20)  Symptoms may include a lump, changes in size, dimpled, redness or scaliness of nipple or breasts,  Treatment  Ultrasonography and biopsy to determine if cancerous  If the tumor is discovered before it has spread, patient has 98% chance of surviving more than 5 yrs. 16

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 Most common cancer in men  Risk factors  Age( more than 60% of cases diagnosed in men over 65)  Genetic predisposition  Diet and Lifestyle  African American and Jamaican men have highest rates in the world 18

 Detection  Blood test: Prostate-specific antigen (PSA)  Rectal exam:  Symptoms may include changes in urinary frequency, weak/interrupted urine flow, painful urination and blood in urine  Treatment  Surgical removal of the prostate and radiation (depends on stage and age)  Radioactive seeds  5-year survival rate is nearly 100% 19

 Cervical cancer  Most cases stem from human papillomavirus (HPV) infection (STD)  Prevention The PAP test is a highly effective screening test for this cancer All sexually active women ages should be tested regularly Gardasil 20

 Types of skin cancer  Basal cell carcinomas  Squamous cell carcinomas  Melanoma (most serious type of skin cancer  Most common form of cancer  1 million cases per year (68,000 are melanoma)  Risk factors  Excessive exposure to UV rays  Common causes are sunburns and suntans  Caucasians are 10X more likely than African Americans to develop basal and squamous cell carcinoma 21

 Prevention  Avoid long term overexposure to sunlight  Detection of Melanoma  ABCD screen test

 The role of DNA (Deoxyribonucleic acid)  Each cells has 23 pairs of chromosomes  Gene: Smaller unit of DNA  DNA mutations and cancer  Mutagens: Radiation, certain viruses and chemical substances  Oncogenes: A gene in which mutations are associated with the transformation of a normal cell into a cancer cell  Tumor suppressor gene: Type of oncogene that normally restricts cellular growth  Hereditary cancer risks  BRCA1 gene 23

 Cancer promoters  Definition: Do not directly produce mutations, they instead accelerate the growth of cells without damaging or permanently altering the DNA Estrogen is an example 24

 Food choices affect your cancer risk by: exposing you to potentially dangerous compounds and depriving you of protective compounds  Dietary fat and meat  Diets high in “bad” fats and meat may contribute to colon, stomach, and prostate cancers  Omega-3 fats are healthier for body  Alcohol  Risk of oral and colon cancer  Fried foods  Fiber  Fruits and vegetables  Phytochemicals  Inactivity and obesity 25

 Microbes  About 15% of the world’s cancers are caused by microbes  Ingested chemicals  Nitrosamines: Nitrates and nitrites found in processed meats that combine with dietary substances and become highly potent carcinogens  Environmental and industrial pollution  Radiation 26

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 Lifestyle choices  Avoid tobacco  Control diet and weight  Regular exercise  Protect skin from the sun  Avoiding environmental and occupational carcinogens  Follow recommendations for cancer screenings 28