What is Cancer lecture

StudyBlue printing of What is Cancer lecture html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, font, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td { margin: 0; padding: 0; border: 0; outline: 0; font-size: 100%; background: transparent; } body { line-height: 1; } blockquote, q { quotes: none; } blockquote:before, blockquote:after, q:before, q:after { content: ''; content: none; } /* remember to define focus styles! */ :focus { outline: 0; } /* remember to highlight inserts somehow! */ ins { text-decoration: none; } del { text-decoration: line-through; } /* tables still need 'cellspacing="0"' in the markup */ table { border-collapse: collapse; border-spacing: 0; } /* end RESET */ .header { min-width:800px; } .logo { padding:6px 20px 2px 20px; margin:0; font-size:25px; font-weight:bold; color:#808285; position:relative; border-bottom: 1px solid #c5c5c5; } .logo-blue { color:#70adc4; } .logo-desc { font-weight:normal; font-size:19px; color:#cccccc; margin-top:50px; position:absolute; display: none; } .back-button { position:absolute; top:20px; right:20px; font-size:13px; line-height:25px; color:rgb(0,175,225); font-weight:normal; } .back-button a { color:rgb(0,175,225); } .instructions { padding:0; margin:0; width:100%; position:relative; color:rgb(100,100,100); } .step-holder { border-left:1px solid #ededed; margin-left:20px; } .steps { padding:15px 0; float:left; width:24%; border-right:1px solid #ededed; text-align:center; } .steps-01 { } .steps-02 { } .steps-03 { } .steps-04 { } .label { padding:5px 10px; } .print-button { } .print-button a { background-color:rgb(0,175,225); color:white; line-height: 19px; padding:9px 8px 5px 30px; font-size:14px; text-decoration:none; background-image: url(images/printer.png); background-repeat: no-repeat; background-position: 7px 50%; -moz-border-radius: 5px; -webkit-border-radius: 5px; } .print-button a:hover { background-color:black; } .theNote .content { width: 8.0in !important; margin: 5px auto; padding:20px; background-color:white; } .theNote .header { border-bottom: 1px dashed #C8C8C8; font-size: 17px; padding: 0 0 10px; line-height: 19px; color: #00ADE1; min-width:500px; } .theNote .body { font-size: 14px; line-height: 19px; padding: 10px 0; } .theNote{ padding:6px 0; clear:both; background-color: rgb(200,200,200); } .theNote h3{ color: rgb(100,100,100); } .theNote h1, .theNote h3{ background-color:white; padding:2px 20px; width:8.0in !important; margin: 0 auto; font-size: 15px; } .theNote h1{ padding-top: 10px; font-size: 15px; } .theNote h1:first-child{ font-size: 20px; } .theNote h3 { font-size: 14px; font-weight: normal; } #options { border: 3px double #ccc; padding: 5px 12px; margin: 10px 50px 10px 20px; float: left; } #info { border-top: 1px solid #ccc; padding-top: 5px; font-style: italic; } li { margin: 5px 10px 5px 25px; } ul li { list-style: disc; } ol li { list-style: decimal; } img { border: 0; } table { clear: both; width: 100%; border: 1px solid #c5c5c5; border-width: 1px 0; margin: 0; page-break-after: always; } table#page { page-break-after: auto; } td { text-align: center; font-size: 12px; border-bottom: 1px dashed #c5c5c5; height: 1.75in; width: 50%; padding-left: 15px; } .leftside { border-right: 1px solid #cccccc; padding: 0 15px 0 0; } .bottom td { border-bottom: none; } .clearfix { clear:both; line-height:1px; height:1px; } img { max-width:80%; max-height:150px; margin:20px; } @media print {.header { display: none; } .content .header{ display:inherit; } table { border: 1px dashed #bbb; border-width: 1px 0; } .theNote{ background-color:white; } } cancer: a group of diseases characterized by uncontrolled growth and spread of abnormal cells metastasis: spread of disease from one part of the body to other parts of the body. cells spread by paths of least resistance-blood, lymph, interstitial spaces types of cell growth normal (physiologic, response, repair): hypertrophy and hyperplasia. Abnormal (disease): dysplasia and neoplasia Hypertrophy: the cells increase in size and normal organization of the cells Hyperplasia: increase in cell number and normal organization of the cells Dysplasia: the cells have disorganized growth Neoplasia: the cells have disorganized growth, the net increase in number of dividing cells and decrease in normal cells Multistage oncogenesis steps: damage to chromosomal DNA of a normal target cell failure to correct DNA repair appearance of specific neoplasia-initiating mutation promotional growth of pre-neoplasm conversion to overtly malignant phenotype malignant progression and tumor spread the diagram of the normal-tumor growth: in the basal lamina, the basal layer is made up of dividing cells where cells divide and one stays in the basal lamina while one moves up the cell stack. in a tumor growth, the dividing cells number increases and breaks up the cell stack creating a tumor cell initiation: an initiating event creates a mutation in one of the basal cells Dysplasia: more mutations occurred. the initiated cell has gained proliferative advantages. rapidly dividing cells begin to accumulate with the epithelium Benign tumor: more changes within the proliferative cell line leads to full tumor development Malignant tumor: the tumor breaks through the basal lamina. the cells are irregularly shaped and the cell line is immortal. they have an increased mobility and invasiveness. Metastasis: cancer cells break through the wall of a lymphatic vessel or blood capillary. they can now migrate throughout the body and potentially seed new tumors. The hallmarks of cancer: self-sufficiency in growth signals insensitivity to antigrowth signals evasion of apoptosis limitless replicative potential sustained angiogenesis tissue invasion and metastasis Genetic instability -fundamental to cancer traits -defects in DNA repair or checkpoint mechanisms key to genomic instability -intact mechanisms keep mutations rates low and prevents accumulation harmful mutations -instability leads to accumulation of mutations that are important requirement for cancer Metastasis -angiogenesis is required for tumor growth -cancer cells invade and spread cell adhesion motility protease production -few cancer cells survive spread through bloodstream -ability to metastasize differs among cancers -blood flow patterns dictate metastasis -some cellular factors associated with invasion and metastasis arise during tumor progression Angiogenesis is when the tumor cells promote blood vessel development in order for it to grow Primary tumor: the initial tumor; the tumor on basal lamina breaks; the malignant tumor cells goes into the extracellular matrix; the cells then enter the circulatory system to whichever target organ or tissue. Myths About Cancer -there is a cancer epidemic in the US-Not true cancer in general is decreasing as time is progressing -If an agent is carcinogenic in animals, it is carcinogenic in humans -not true animal models are not necessarily good predictors of cancer risks in humans background rates of cancer vary considerably among and within species sensitivity to physical.chemical/biological carcinogens varies considerably among species -if an agent is carcinogenic at high dose, it is carcinogenic at low dose-not true the dosage at lower doses are from different factors and that from high doses from different factors about 90% of cancers are environmental-not true some are from genetic susceptability Major Causes of Cancer -major casual factors are smoking and diet and certain viruses -environmental pollutants and pesticides contribute very little to the cancer burden -artificial sweetners, hair dyes and cell phones do not cause cancer types of cancer carcinomas -arise from epithelial cells -account for about 90% of all cancers sarcomas -arise in bone, cartilage, blood vessels, fat, muscle -account for about 1% of all cancers leukemias and lymphomas -arise in bone marrow and lymphatic tissue -account for about 10% of all cancers Acute lymphocytic leukemia the top picture: it indicates normal bone marrow. The posterior iliac crest in a middle aged person and is about 50% cellular. the bottom picture: all-marrow is nearly 100% cellular and consists of leukemic cells that have virually replaced or supressed normal blood cell formation. Melanoma -human microinvasive melanoma exhibit solitary and nested atypical melanocytes along and above the dermal-epidermal junction, so called 'pagetoid speading' -comparable lesion in a UV-irradiated HGF/SF-transgenic mouse. cancer is a group of diseases characterized by the uncontrolled growth of abnormal cells carcinogenesis is a multi-stage process involving initiation, promotion and progression dysplasia and neoplasia are abnormal tissue growths characterized by tissue disorganization there are over 100 different types of cancers cancers are identified by differences in sites of origin and cell types involved benign tumors grow in confined areas; malignant tumors (cancers) can spread to distant sites. many cancer cells develop ways to evade immune attack tumor cells have the capacity to grow blood vessels (angiogenesis) to supprt tumor growth and metastasis cancer cells can invade neighboring tissues and penetrate blood vessels because of decreased cell-cell adhesion increased motility and capacity to break down the extracellular matrix and basal lamina Cancer cells generally metastasize to the tissue with the first capillary bed after entering the bloodstream. some cancers have an organ-specific pattern of spread cancer properties vary with time. as tumor cells divide and the cancer grows, cancer cells often divide more rapidly, become more invasive and spread more easily. cancer cells may also become more resistant to therapy. metastatic potential is believed to be acquired in late stages of cancer development