Chapter 16

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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: Mass of cells that 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.

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

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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 Staging is based on size

 Classified according to types of cells that give rise to them  Carcinomas – arise from epithelial tissue Ex., skin  Sarcomas – arise from connective tissue Bone, cartilage, etc.  Lymphomas- arise from lymph nodes  Leukemias - Cancer of the blood- forming cells in bone marrow.

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

 Leading cause of cancer deaths in the U.S.  ~158,000 deaths/year  Risk factors  Tobacco smoke (including ETS) contributes to 90% of lung cancer deaths  Detection  Symptoms: Persistent cough, chest pain, or recurring bronchitis  Difficult to detect early and symptoms usually do not appear until the invasive stage  Diagnosis: CT scan, chest x-ray or sputum examination, bronchoscopy

 Treatment  If caught early, localized cancers can be treated with surgery  A combination of radiation and/or chemotherapy can be used in addition to surgery

 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

 Detection and treatment  Symptoms: bleeding from rectum and changes in bowel habits  Regular screening tests are recommended beginning at age 50  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: inheriting mutated BRCA1/2 genes Age: Most common in women over 50 Early onset of menstruation First child after 30 Current use of HT Unhealthy diet and lifestyle

 Detection  Symptoms may include a lump, changes in size, dimpled, redness or a scaly of nipple or breasts  ACS recommends 1 mammogram/year (women over 40)  Clinical and Self breast exams (starting at age 20)

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 Treatment  A cure is most likely if detected early  Removal of the tumor if discovered before it has spread.

 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

 Detection  Symptoms may include changes in urinary frequency, weak or interrupted urine flow, painful urination, blood in urine  Blood test: Prostate-specific antigen (PSA)  Rectal exam

 Treatment  Surgical removal of the prostate and radiation (depends on stage and age)  Radioactive seeds

 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 A vaccine against HPV is Gardasil

 Main types of skin cancer  Basal cell carcinomas  Squamous cell carcinomas  Melanoma (most deadly type)  Most common form of cancer  1 million cases per year (68,000 are melanoma)  Risk factors  Excessive exposure to UV rays  Pale skin, easily sunburned  Caucasians are 10X more likely than African Americans to develop basal and squamous cell carcinoma

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

 The role of DNA mutations and Cancer  Mutagens: substances that cause mutations like radiation, certain viruses, ingested chemicals, environmental pollution  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  If a hereditary cancer, abnormal gene is present in sperm/egg  If not hereditary, a mutation has occurred  Tobacco Use  Dietary Factors -fried foods, low fiber, lack of phytochemicals from fruits and vegetables.  Inactivity and Obesity

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

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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 26