Topics for Micro160 Exam 3 Note Please review lecture slides as well this should not be the primary form of studying This study guide was uploaded by the professor The Exam will cover material from Lecture 23 through Lecture 31 Study Guide covers material in lecture 32 Screening for cancers What is screening What is the goal of screening This is a systematic search for cancer before any symptoms become apparent Main goal is to identify treatable cancer early and thus increase the chance of Goal 1 is to detect cancer early survival survival Screening is strictly for people who have symptoms or reasons to believe they have cancer True or false False early detection before symptoms become apparent increases chance of Many people need to be screened in order to benefit the relatively few individuals who will be identified correctly with cancer The more people that are screened the more of a chance that they can catch something early Define false positives and false negatives What do false positives and false negatives have to do with screening False positive is a test saying that a patient has cancer when they actually don t False negative is a test for cancer showing up negative when it is actually Screenings can come up either negative or positive and a false one of either can positive be devastating What are the pitfalls of cancer screening Why are aggressive cancers sometimes missed even with routine screening Pitfalls include false negatives People who are screened often die of cancer Screenings have a larger chance of missing smaller windows that are crucial to detecting early stages of aggressive cancers What is overdiagnosis Screening tends to detect more of the slow growing indolent cancers How does this fact relate to overdiagnosis It is the treatment of cancers that is unnecessary The cancer could have gone away on its own or never would have resulted in death or symptoms There are unnecessary side effects Can screening tools be dangerous to your health X rays can cause other cancers Colonoscopy can cause tears in the lining of the colon For yourself what kind of things should you know about screening protocols Do you wanna be one of those people who just does what your doctor says Why if your doctor starts talking about 5 year survival rates associated with screening should your ears perk up and questions start spewing out of your mouth Yes take responsibility and screen when you deem it necessary and be aware of the risks Screening may detect a cancer earlier but not affect the age of mortality What question are you going to want to know the answer to the most when a screen is suggested for you I ll tell you Does the screen significantly reduce cancer specific mortality rates 1 000 people screened over a decade Possibly only 12 of these people will actually die from cancer if left to progress Screening may identify 3 of these people What are the trade offs between screening sensitivity and specificity How does sensitivity and specificity each relate to false positives and false negatives Sensitivity The percent of people with a given cancer accurately identified during screening Not specific increased false negatives Specificity The percent of people without cancer that are correctly identified as being cancer free Not specific increased false positives Low sensitivity high specificity High sensitivity low specificity Why are PET Scan s cool Hint metabolic activity of cells They are imaging techniques that produce a 3 D image The solution will detect active spots of growth high metabolic activity in cells Cancer s Cure s What are the recent hypotheses for why large animals such as elephants have fewer cancers than humans That there is little relationship exists between body size and cancer rates among animals This is part not all of the answer Elephant cells with damaged DNA appear to favor apoptosis over DNA repair which is great way to not even risk proliferating unwanted mutations Related to the above how does radiation result in cell death It mutates DNA which can result in uncontrolled cell proliferation in order to prevent this the cell goes into apoptosis The standard treatments for cancer were in use before we even understood much about cancer What are the standard treatments for cancer Surgery Radiation Chemotherapy Understand how each of these standard treatments work Surgery Removal of the tumor or part of the tumor Chemotherapy Treatment of cancer with one or more drugs that are cytotoxic and focus on cells in tumors as part of a standardized regimen two types traditional which kills rapidly dividing cells And targeted antibody therapy There are over 100 different drugs available Radiation Medical use of ionizing radiation damages DNA of cells induces apoptosis They are given in fractional doses What did I pose that future treatments for cancer may be like Why might there not be a silver bullet to cure cancer They all need to be different since there is a large genetic diversity between each and every cancer case So there might not be ONE silver bullet HIV Origin and Biology What year did AIDS become evident to the medical community 1981 What were the strange diseases with which clusters of young gay men were being diagnosed ushering in the AIDS epidemic hint I could barely pronounce them in class Karposi s Sarcoma rare form of relatively benign cancer that tends to occur in older people Pneumocystis pheumonia The social stigma prejudice against homosexuals prevented a full blown effort to fund research to understand what was causing AIDS and how to treat it which lead to large activist movement and home grown awareness and testing programs They protested to get proper healthcare What is AIDS What is HIV Are they different Does HIV cause AIDS You would be a if you stated that HIV does not cause AIDS AIDS Acquired Immune Deficiency Syndrome AIDS is a advanced stage of HIV infection You would be a critic HIV stands for Human Immodeficiency Virus This type of thinking caused president of to delay access to HIV medication among his governed people which makes him and his policies responsible for the of over people 1 Mbeki 2 South Africa 3 Avoidable deaths 4 A third of a million This contrasts with Thailand how The main HIV 1 strain that is most responsible for the global AIDS epidemic has an interesting origin Be familiar with it and know in which animal the most similar virus to HIV is found They both have the same modes of transmission HIV 2 progresses more
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