good morning good afternoon good evening this is Dr deshavo and we today will be reviewing chapter 11 biology of cancer this is a great topic to review because unfortunately there are fair amount of people with cancer I'm sure you will care for and it's good to have that basic knowledge of the disease process to help you facilitate your care with your patients so cancer is abnormal cells which divide uncontrollably and are able to actually invade into other tissues normal non-cancerous cells so those cells get next to other healthy cells and say okay this is as far as I should go and they stop growing cancer does not it starts to invade into other tissues our immune system doesn't recognize it because of that glycoprotein layer on the outside of it it can kind of start to destroy the surrounding tissues by either breaking into those tissues or creating too much space because generally areas in our body especially nerves don't like excess pressure so those cancerous cells can also provide excess pressure so derived from the Greek word for crab and it's also known as endoplasm but don't get confused with that because neoplasm can also reference the nine tumors as well that's kind of an overarching term meaning both so benign you can see slower and it's encapsulated so nine tumors generally literally have oh I have a picture hold on really really like pictures it helps me and I had pulled up benign there we go and don't turn me into Shutterstock because I steal stuff from them occasionally but not all this time so this is both examples in benign neoplasm and neoplasm can also reference cancer so this is benign this is cancer and benign literally has a capsule around it in that castle just to keep the cells in place I mean don't get me wrong you can grow bigger but it generally grows slower and that capsule helps to hold it in place now can that still cause problems absolutely it can push on things around it benign tumors in the brain can cause issues nerves do not like pressure so yes benign tumors can cause problems but not like malignancies can and Cancers can you can see that they are not encapsulated they've lost that contact inhibition and they're starting to invade down through the tissues and the real problem other than evading into tissues is you can see I like this picture because it shows it can either get into the blood or it could get into the lymphatic system which are two systems that go throughout our body through which these malignant cells can pass so kind of yucky either way um so you can read through the rest of those non-invasive well-differentiated it's its own cells it stays in its own location this is poorly differentiated can change and mutate and be all different types of cells look mitosis is a replication of cells so this is though this is high metastasis is the ability of it to spread into the bloodstream and or the lymphatic okay so benign tumor is Probably sounds somewhat familiar if any of you have dogs boy my little girl sure likes to make lipomas and makes me nervous because I feel them and she has a couple small couple big but lipoma are fat cells lipo is a prefix for fat those are fat cells that are benign they tend to be encapsulated biomyoma could be smooth muscles of uh in the smooth muscle of the uterus I have several of these fibromas an example of ones in the breast meningioma is in the meninges those surrounding structures of the brain which we will get into in the future and of course those are just to sort of start to correlate that prefix meningitis right there's going to be inflammation those surrounding protective layers around the brain and the spinal cord these can progress to cancer they also can't so hopefully we hope for the best malignant tumors are named according to the cell type from which they're alive all right I have a little article that I do want to point out too but let's get through the notes first these two kind of can be lumped together but once again you want to know what is given to you in these lectures carcinoma comes from epithelial tissues don't get nervous it's pretty easy it's all the Linings of the body your skin the inside of your mouth the lining of the GI tube the lining of the respiratory tube the lining of urogenital tubes okay so any Linings have epithelial tissues from which carcinomas can come like a skin cancer adenocarcinoma more specifically comes from the duct or the glandular tissue but you can actually sort of sub this under carcinoma they're very closely related the third coma could be connective tissues ligaments bones I have a really good article about that for you as achymal tissues are the embryological precursor to muscles and bones and connective tissue so that's why they said mesenchymal tissues lymphota lymphoma is your lymphatic tissue which I'm sure you're all aware of and then leukemias from those blood forming cells like I said I pulled up this one here we go so this is from I don't know if I can move my Cleveland Clinic there we go um just to give you a little bit more look into Dental carcinoma um so carcinoma is cancer from the epithelial tissues here is a picture of cancer cells that are happening in a dental carcinoma which is glandular tissues so and you are really along you know mouth GI attract um Poland you have ducts so it could come from those surface cells which are the epithelial cells or glandular cells which align the whole organs you know going down and the biggest one really with the adenocarcinoma would be choline cancers so personal and filial tissues um leukemia starts in the bone marrow myeloma we didn't really go over that you can kind of lump in with blood cancers per se lymphoma will be in the lymphatic sarcoma will be in those connective tissues um in situ we're going to talk about invasive and metastatic we will talk about and then that adenocarcinoma is going to be in your glands and then don't forget we have the carcinomas which include the Skins which will come from the squamous cells um ductile in the breast milk ducts would be a dental carcinoma to give you an example and then um I just thought that was a pretty good summary and sort of went more in depth with that I mostly wanted to show you those pictures start just to give you visuals I do so well with visuals stop so don't forget lymphoma will specifically there's some overlap okay we'll specifically reference those um lymph tissues we could also get sarcomas I think sarcomas are mostly with bone and muscles and ligaments and cartilage nerve cancers have more specific names and then you could get lipomas that can become cancerous okay but for us we'll stick with what is in the notes but I just wanted to give you some additional information that I hope is helpful so carcinoma will be those epithelial tissues such as your skin cancer Dental carcinoma is in ducks or gland tissues we see that with you know duct issues in the colon and also the breast sarcoma could be muscle could be bone lymphoto and lymphatics and then blood will be your leukemias in situ means that it is still in place it hasn't broken through What's called the basement membrane of the connective tissue or skin that it is located in with your skin if you have a carcinoma you have a basement layer that's a loose connective tissue and if this is the surface of your skin yeah so if you were to actually touch the surface of your skin here's the top here's that basement layer it means that that cancer is still above that basement layer and it hasn't broken through it or through that connective tissue you know hopefully if you have some sort of cancer you catch it when it's there it's very early stages and hopefully get rid of that for example if you have melanoma they will actually cut out a good you know four to five inches this way and then you know width wise and then they look to make sure that the cells are not on the periphery and then they have to go in and take out more positively test lymph nodes so hopefully within situ it's located they get it and it hasn't spread yet foreign let's read through this very carefully pause it if you need to read every single word of the question and the answer and then looking at the next one the answer is D so cancer is a malignant tumor benign which are not invasive or not cancerous malignant tumors have rapid growth neoplasms maybe benign or cancerous and once once again always read these answers because I think there's some things in here that aren't in the previous notes laughs okay so cancer is very common it's probably why we don't have a cure for it yet not only is it complex in general there's uh many many different types of cancers so the tumor especially initially can be a mix of cancerous and benign cells what begins to happen are these three stages here initiation is damage to the initial cell's DNA so once again we have damage to cells all the time our immune system can generally get to them and fix them but occasionally it goes awry that is tumor initiation The Next Step will be a promotion where we start to change those cells into cells that are not the initial type we start to get you know misformed abnormal cells that will then eventually progress into cancerous cells and that's tumor progression multiple mutations in that DNA may be required and there are different and various types of driver mutations that drive that progression of cancer and damage to that DNA to keep sort of pushing it in the direction of that cancer until after a critical number of those mutations the cell finally transforms into being cancerous then it will continue to mutate the cells around it in what's called clonal proliferation or expansion those cells will replicate and grow in over a course of complex steps those mutations eventually will become stronger and kind of the strongest ones will start to win and clone themselves in that proliferation or expansion it gives it the advantage over its neighbors and this is how cancer grows it gets increa increased growth rate the cancer cells I mean and it decreases and I think we went over that in case we didn't that is program cell death that is one of the ways that we first cancer in our own bodies where our body is saying wait a minute this is not a proper cell I'm going to kill it off and with cancer it evades that ability for our body to kill it and continues to grow so primary changes in its genome its DNA allow it to proliferate and also to allow signaling for surrounding cells to mutate and proliferate it evades our bodies um growth suppression our body's recognition that that cells are going awry the DNA itself is not stable those genomes the genomic the genes in the DNA are not stable and they get misformed we're going to look at that in a slide or two and it can replicate forever in immortality secondary to those genetic changes we have angiogenesis angio refers to blood vessels Genesis is the creation of it and these cancerous collections of cells start to get its own blood supply and they're very greedy with energy and if you think for a second about patients you've dealt with when we have cancer when they have cancer excuse me they lose weight they lose weight because the cancer uses a ton of energy so depending on how far it has progressed they may have lost more weight and that is part of the reason why Hallmarks of cancer tumor resistance to destruction these cells will fight that apoptosis they also promote inflammation they have viewed avoid our immune system and don't forget they avoid our immune system because the cell surface kind of puts us into a stealthy State those cancerous cells they hide from our immune system it can in fact activate Invasion and metastasis into the surrounding tissues blood system and the lymphatic system this kind of goes through everything that we have already reviewed so just review that on your own and you know visuals sometimes help you I know they've helped me remember some of the things on exams that I needed to remember um uncontrolled cellular proliferation I think we've Hit Upon This a time or two normal cells and proliferative states in response to growth factor those cancer cells are uncontrolled normal cells are controlled they have that contact inhibition and they also have something called proto-oncogenes which are genes that direct that normal cell proliferation seeing okay we have enough cells we can stop replicating but these genes that are called proto-oncogenes can get damaged and turn into oncogenes which are mutated forms of proto-onco genes or overexpressed ones and these aren't going jeans can close it uncontrolled cell growth they also can secrete factors that stimulate their own growth and create more of those cancer cells so oncogene you know so this damaged Gene one of them that is mutations response so that is excuse me for a second and knees it will be right back so there is an earliest Gene that regulates the signaling I'm sorry excuse me of cells around it and replication of cells this can be damaged and that is one of the specific genes that can be damaged but you can also avoid our quote translocations in these translocations can actually cause genes to be relocated to other locations and there are a few examples underneath that provide with those translocations the outcomes of those translocations access an inappropriate production of a proliferation Factor can cause burkett's lymphoma which is one example of a lymphoma production of Novel proteins with growth promoting properties is expressed with chronic myeloid leukemia and Gene amplification where you have an excessive amount of genes in that cell created so evading growth suppressors in cancerous cells we have the ability to evade these tumor suppressor genes or anti-ampo genes they in regular cells regulate cell cycle inhibit inhibit proliferation stop cell divisions if the cells are damaged and prevent imputations you know in cancer they can evade these normal processes so some other issues that can have been with both suppressors is an inactivation of tumor suppressor genes so these are normal genes that are in the body that regulate normal cell growth okay so we have a retinoplastoma it's actually one gene in tumor protein p53 also known as tp53 um and these in normal healthy people can regulate cell growth to a proper level we can inactivate them with cancer so you can get and of course you know the retinas in the eye excessive growth of these cells leading to cancer and these are throughout the body so that's the deal with those and it damages these genes which can allow for that unregulated cell growth normally in humans you have two copies of each of these tumor suppressor genes like with this retinoblastoma one you have two you can still fight off excess cell growth with just one for an example two mutations would be necessary on both of them and then um a single germ cell mutation so this would be a sperm or an egg also known as an oocyte can also cause transmission of cancer causing genes you could get instability in the genes as well don't forget the genes are in the DNA and um you can get an increased tendency for mutations during life cycle of the cell so rate you can have more chances for cancer there are caretaker genes that help in repairing DNA and mutations can happen in those damaging that genomic stability you can also have what is called epigenetic silencing or modulation of Gene functioning this epigenetic silencing silences the proper function of Gene function and replication so that way they cannot create the proper proteins in the cell they that cell cannot function properly if they can't make the proper proteins you can also have chromosome instability that makes sense if you have damage to the chromosomes the chromosomes don't forget are the genetic code that's in the DNA you can have loss of chromosome you could have loss of the replication of them amplification excuse me is going to be excessive amount of those chromosomes so we spoke about replication mortality cancer cells can live forever normal body cells are not Immortal they only divide a limited amount of times because after a while they have to have fresh new cells Okay so telomeres are protective caps on each chromosome there's been some research into this and these telomeres actually can get damaged over time and cells so they are held in place by an enzyme called telomerase they prevent that immortality allowing fresh new cells to begin a new lineage of cells to be replicated from okay and they also become smaller with each cell division eventually leading to the cell dying you know from that lineage so in allowing new fresh cells to be recreated thank you there you go so with cancer cells they can allow this telomerase to be continually produced and they can just keep reproducing that gives you kind of a picture I'm not sure if that's really very helpful or not and you can see the DNA coming out here is where the telomerase activity happens and cells can keep replicating you know with adult cells you eventually from one lineage and you know you can create brand new ones but from one lineage it's only going to replicate so many times before it dies off and fresh new cells will begin from the very beginning with those cancer cells they can just keep going because that enzyme activity from telomerase is continuing to move on and being active angiogenesis is a creation of new blood cells angiogenesis is important in all tissues if you damage a certain area of the body you have to have new blood vessels so you can create new tissue the thing with Cancers is it also gets its own brand new blood supply and it's essential to the growth in the spread of that cancer cancer is extremely mitotic so it needs blood so it can create energy from glucose and oxygen cancerous tumors maintain a secretion of angiogenic factors okay and these are factors that help to perpetuate the growth of those blood vessels and they obviously will suppress angiogenesis inhibitors foreign