2Introduction Causes about 565,000 deaths in the U.S. each year 1500 per dayLeading cause of disease related death among people under age 65.Second most common cause of deathEvidence 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
3Figure 16-1 Percentage of all cancer deaths linked to risk factors
4What is Cancer?Definition: an abnormal and uncontrollable multiplication of cells or tissue that can lead to death.Tumor: a mass of tissue that serves no purpose.Benign versus malignant tumorsBenign tumor: mass of cells enclosed in a membrane that prevents their penetration of other tissues.Malignant tumor: (Neoplasm) cancerous, can invade surrounding tissues.Every case of cancer begins as a change in a cell that allows it to grow and divide when it should not.
6Metastasis Primary tumor Definition: the spreading of cancer cells from one part of the body to another, occurs because cancer cells do not stick to each other as strongly as normal cells.Metastasizing – the traveling and seeding process of cancerous cellsCells break away from primary tumor and invade surrounding tissues or travel through the blood and lymphatic system.New tumors are calledSecondary tumor or metastases
7Types of Cancer Malignant Tumors The behavior of tumors arising in different body organs is characteristic of the tissue of originClassified according to the types of cells.Initially retain some of the original properties of the host cell.Carcinomas - most common - arises from the epithelial tissue that cover body surfaces. Linings, tubes, cavities and secretion glands.
8Types of Cancer Malignant Tumors Sarcomas: arise in connective and fibrous tissues. Bone, muscle, cartilage and membranes covering muscle or fat.Lymphomas: Cancers of the lymph nodes.Leukemia: cancer of the blood-forming cells in bone marrow.
9Figure 16-3 Cancer cases and deaths by site and sex
10The Incidence of Cancer 1.4 million Americans are diagnosed yearlyAmerican Cancer SocietyEstimates that the 5-year survival rate for all cancers diagnosed between 1996 and 2003 is 66%1 in 2 men and 1 in 3 women will be develop cancer during their lifetime.
11The Incidence of Cancer Since 1991 the death rate has dropped 18% in men and 10% in womenPreventionEarly detectionImproved therapyAmerican Cancer Society estimates90% of skin cancer could have be prevented87% of lung cancer could have be preventedRegular screening and self-examinations could save an additional 100,000 lives per year.About 10.8 million living Americans have a history of cancer.
12Lung Cancer Most common cause of cancer death in the U.S. 162,000 deaths per yearRisk FactorsTobacco smoking contributes to 87%.Combined with environmental carcinogens multiply by a factor of 10.Detection and Treatment (Difficult to detect)Symptoms are not detected until cancer has reached the invasive stage.Persistent cough, chest pain, or recurring bronchitis.Diagnosis - chest x-ray or sputum examination - fiber-optic bronchosectomy.
13Lung Cancer Treatment: Difficult to treat. Caught early treated by surgeryOnly 16% are detected prior to spreadingRadiation and chemotherapy are used in additionDetected early 49% of patients are alive 5 years post.Overall the survival rate is only 15%Phototherapy, gene therapy, and immunotherapy are being studied.
14Colon and Rectal Second leading cancer causing death. Risk Factors Directly linked to diet and genetic predisposition.90% occurs after 50 yr. of age.HeredityLifestyleUp to 1/3 of the population is genetically prone.Detection and TreatmentDiet low in fat and High in fiberScreeningSigmoidoscopy or colonoscopyExamine for polypsSurgery is primary treatmentRadiation and chemotherapy used prior to surgery
15Breast Cancer Most common cancer in women Causes almost as many deaths in women as lung cancer1:7 American women will develop it during her lifetime (182,000).1:30 Will die from the disease (41,000 deaths).Risk FactorsMost common in women over 50“Disease of Civilization”Common causes: Genetic predisposition, High fat, High calorie diet and Sedentary lifestyle, Alcohol use, early onset of menstruation, First child after 30 and obesityCurrent use of Hormone Replacement Therapy (HRT)Estrogen -cancer in estrogen-responsive sites
16Breast Cancer Detection and Treatment Early detection. Treatment Monthly breast self-exam for all women over 20.Clinical breast exam by a physician every 3 yr.Mammography- Every 1-2 years yr. old.Over 50 every year.Digital MammographyUltrasonographyTreatmentBiopsiedSurvival rate98% if the cells did not metastasized89% for all stages at 5 years80% at 10 yearsNew strategies for treatment and prevention
17Prostate Cancer Most common cancer in men. Second leading cancer death in men186,000 new cases per yearMore than 28,000 deaths per yearRisk FactorsAgeDietLifestyleGenetic predispositionEarly detection is key.Prostate-specific antigen (PSA) blood testDigital rectal examUltrasoundTreatmentsurgical removal of the prostate and radiationSurvivalAll stages near 100% after 5 years
18Cancers of the Female Reproductive Tract Cervical cancer - sexually transmitted.Most cases stem from infection by the human papillomavirus (HPV)- transmitted by unprotected sex.Group of about 100 related virusesWomen high in HPV 16 are at a high riskSmokingInfection by genital herpesCervical cancer most common in women in their 20’s and 30’s.Factors: sexual intercourse before 18, multiple sex partners, cigarette smoking and low socioeconomic status.Screening:PAP TestCervical dysplasiaAll sexually active women ages should be testedTreatmentSurgeryCryoscopic probeLocalized laserVaccination of girls as young as 9 and women through age 26
19Cancers of the Female Reproductive Tract Uterine, or Endometrial:Occurs after 55Risk factors similar to breast cancerDetermined by Pelvic ExamTreatment is surgery95% survivability after 5 yearsOvarian Cancer:Difficult to detect and diagnosis, No warning signsFamily history or genetic factorsDeterminedPelvic ExamUltrasound of ovariesTreatment is surgical removal of the ovaries, the fallopian tubes, and the uterus.Radiation and Chemotherapy are sometimes used.Survival rate after 5 years is 92% for localized tumorSurvival rate after 5 years for all stages is 45%
20Skin Cancer Risk Factors Types: Prevention Detection and Treatment Most common form1 million cases per year62,500 are melanomaMost seriousEasily detected and highly curableRisk FactorsExposure to ultraviolet rays during childhoodCommon cause - sunburns and suntansCaucasians are 10X more likely than African Americans to develop melanomaTypes:Basal and SquamousMelanoma - more dangerous formPreventionAvoid long term overexposure to sunlightBlistering and peeling sunburnsDetection and TreatmentABCD screen test
22Other Cancers Oral Cancer Testicular Cancer Pancreatic Cancer Lip, tongue, mouth, and throatSmoking and tobacco useTesticular CancerRareMost common n men age 20-35Pancreatic Cancer3 out of 10 are linked to smokingStomach CancerTwice as common in malesInfected by Helicobacter pyloriBladder CancerThree times more likely in malesSmoking is the key risk factorKidney CancerSmoking and obesity are mild risk factorsBrain CancerDevelops for no apparent reason
23Leukemia Cancers of the white blood cells. Starts in the bone marrow but spread to the lymph nodes, spleen, liver, other organs and CNS.Abnormal production of immature white blood cells; rapidly growing cells displace red blood cell precursorsImmature WBC’s cannot fight off infectionsRisk factors are unknown20% of cases of adult leukemia are related to smokingAbout 44,000 new cases and 22,ooo deaths each year.
24Common Cancers Lymphoma Multiple Myeloma Arising from the lymph cells Hodgkin’s diseaseNon-Hodgkin’s disease (NHL)More commonMore deadly (6th most common cancer)Risk factors are not well understoodCompromised immune system are at a greater riskMultiple MyelomaMalignant plasma cells produce tumors in the bone marrow.Leads to anemia, excessive bleeding and decreased resistance to infectionAge is most significant risk factor – average age is 70
25The Cause of Cancer The Role of DNA (Deoxyribonucleic acid) Each cells has 23 pairs of chromosomesEach controls the way a cell will workEach rung is made up of four different nucleotide bases:Adenine, thymine, cytosine and guanineA gene – smaller unit of DNADNA Mutations and CancerChanges the way the cells functionMutagens – radiation, certain viruses and chemical substancesOncogenes – a gene involved in the transformation of a normal cell into cancerTumor suppressor genes – type of oncogene that restrains cellular growthHereditary Cancer Risks
26Promoters Cancer promoters Cancer initiators: Do not directly produce mutations, they accelerate the growth of cells without damaging of permanently altering the DNA.EstrogenCancer initiators:Carcinogenic agentsUV radiationCigarette smoking is a complete carcinogen because it is a cancer initiator and promoter.
27Dietary FactorsYour food choices affect your cancer risk by exposing you to potential dangerous compounds and depriving you protective ones.Dietary Fat and MeatAmerican Cancer Society encourages everyone to limit their consumption of processed and red meats.Contributes to certain cancers:Colon, stomach, and prostateAlcoholFried FoodsDietary FiberFruits and VegetablesAnticarcinogensCarotenoidsAntioxidants versus Free radicalsPhytochemicalsSulforaphane
29Inactivity and Obesity Linked to breast and colon cancer.Benefits of Physical ActivitySpeeding the movement of food through the digestive systemStrengthen the immune systemDecreasing blood fat levelsPrevention of obesity
30Microbes About 15% of the world’s cancers are caused by microbes VirusesHuman papillomavirus – cervical cancerBacteriaHelicobacter pylori – stomach cancerEpstein-Barr virus (mononucleosis) – Hodgkin’s disease, cancer of the pharynx and some stomach cancersHuman herpesvirus 8 – Kaposi’s sarcoma and certain types of lymphomiaHepatitis B and C – cause as many as 80% of the world’s liver cancers.Parasites
31Carcinogens in the Environment Ingested ChemicalsNitrosamines – Nitrates and nitrites combining with dietary substances - highly potent carcinogenEnvironmental and Industrial pollutionRadiation - UV rays or man made
32Detecting,Diagnosing, and Treating Cancer Self-monitoringCAUTION acronymDiagnosing:BiopsyMagnetic resonance imaging (MRI)Computed tomography (CT)UltrasonographyTreatment:SurgeryChemotherapyRadiation TherapyNew and Experimental:Gene therapyBone marrow and Stem Cell transplantsBiological therapiesProteasome inhibitorsAnti-angiogenesis drugsEnzyme activators/blockers
33Figure 16-8 The seven major warning signs of cancer
34Living with Cancer More than 10 million cancer survivors in the U.S. Economic prejudiceFace prejudice from health insurersRefuse to issuerenewalFinancial impactPsychological support is important
35Preventing CancerLifestyle choicesAvoid tobaccoControlling diet and weightRegular exerciseProtecting skin from the sunAvoiding environmental and occupational carcinogens Recommended screening testsFollow the American Cancer Society’s recommendations.Appropriate timing and methods for screeningsBe aware of the early signs and symptoms