in part two of chapter six you will learn how tumors are named features of invasion and metastasis and how tumors are diagnosed graded and treated there are some general rules that are followed when it comes to naming tumors first of all tumors are commonly named from the parenchyma or the functional tissue that they come from benign tumors end in oma some examples here are fibroma which is a benign tumor of the fibrous tissue chondroma which is a benign tumor of cartilage tissue for malignant tumors if it's in the epithelial tissue then we will call it a carcinoma so an example would be squamous cell carcinoma if it's from a glandular tissue we would call it adenocarcinoma or from melanocytes it's called melanoma mesenchymal tissue or connective or soft tissue would be a sarcoma this can be a little confusing because this um melanoma ends in actually noma in oma not just oma so again it's not foolproof but you can generally tell if a tumor is benign or malignant by its name and you should look at table 6-1 in the text to see more examples for the nomenclature of naming tumors you can expect one at least one question on the exam about naming a tumor some characteristics of benign tumors include the cells tend to resemble normal tissue in that they're well differentiated and they can perform the function of the normal tissue for example if the tissue like a thyroid tissue is supposed to secrete hormones then you could have an over secretion of thyroid hormones if you have a thyroid tumor benign tumors tend to grow slowly they're also surrounded by a fibrous capsule and that capsule keeps them from infiltrating or invading or metastasizing they can damage nearby organs however by compressing them i've been a benign brain tumor can still be devastating because the tumor can compress normal brain tissue and cause lots of serious symptoms like seizures and even death malignant tumors contain cells that do not look like the tissue of origin and they're unable to perform the normal functions of the tissue the tumor may secrete signals enzymes toxins etc remember that malignant cells and thus malignant tumors tend to proliferate rapidly and they can continue to mutate they don't have capsules like benign tumors do and they tend to send legs into the surrounding tissue the actual word cancer means crab or legs crab based on these legs because people thought the cancers looked like crabs also malignant cells can enter and leave blood vessels and through the blood vessel in the bloodstream be carried to other parts of the body this is called metastasis there are two categories of malignant neoplasms solid tumors and hematologic cancers solid tumors are initially confined to a specific organ or tissue but they will eventually eva invade and break through the original tissue ultimately entering the bloodstream and the lymphatic channels from there they are carried to other parts of the body hematologic cancers are already spread throughout the body because they're in the bloodstream an example of a hematologic cancer would be leukemias or lymphomas and we'll talk more about leukemias and lymphomas in a later chapter cells that remain localized and have not yet crossed the basement membrane are referred to as cancer in situ this is a really early stage of cancer and is generally considered 100 curable let's talk a bit more about metastasis when cells in a primary tumor lose adhesion escape and travel to another point in the body that would result in a secondary tumor there may be some mutation but generally we would expect the primary and the secondary tumor to look a lot of like as mentioned the metastasis would happen via blood or lymphatics sarcomas tend to metastasize more frequently via blood while carcinomas tend to metastasize more frequently via the lymph channels for cancer to develop which is carcinogenicity carcinogenesis there needs to be initiation or in other words there has to be a mutated cell and that mutated cell will go through mitosis and division and multiply fairly rapidly that's called the promotion phase of cancer and finally tumor cells will begin developing more mutations and competing with another one another four resources which makes them more aggressive and this is the progression stage of the disease for a cancer to survive angiogenesis must take place so the cancer cells have the ability to grow their own new blood vessels how they do it we don't fully know but we are there's a lot of research going on to understand the angiogenesis capability of cancer cells there's a long list of factors that cause cancer first of all there are genetic links for certain types of cancers you've probably heard of the brocco one brocco ii gene or there's also problems with the retinoblastoma gene the rb so women who carry the bronco gene are at increased risk for breast cancer and ovarian cancers men who carry the gene would also be at higher risk for male breast cancer as well as other cancers like melanoma and pancreatic cancer reproductive hormones can also be associated with cancer development for example breast cancers are tested in terms of how they behave around estrogen or progesterone estrogen positive breast cancers are treated with estrogen blocking drugs and that keeps the estrogen from feeding the tumor cells persons who are obese have higher risks of cancer this is thought to be due to an overproduction of insulin and insulin-like growth factors overproduction tends to stimulate cell division and inhibit apoptosis and finally we're we develop these would-be tumors all the time but luckily our immune system is able to recognize and kill them this process might be inhibited if people have immunodeficiencies so the immune system is just not working correctly also cells can change the expression of the proteins on the surface and that change in the genetic expression hides them from our immune system cigarettes alcohol diet all have um known been known to damage dna rna or to it hurt the proteins that are involved in cell cell proliferation radiation directly damages dna or resulting in gene or chromosome changes viruses and bacteria may stimulate changes in normal cells that would result in a tumor for example the hpv virus can cause it um and stressing a stressful environment i guess i should say in the cervix or um in the esopha esophagopharyngeal area and these can cause tumors in fact hpv is found to be the most common reason for women to develop cervical cancer the epstein-var bar virus which is the virus that causes mononuclear mononucleosis has been associated with b-cell cancers and burkitt lymphomas patients with hepatitis b and c show an increase in their rates of liver cancer and human t cell leukemia virus is a retrovirus that affects t cells and can lead to a proliferation of t cells i suspect many of you have known people with cancer and some of these systemic symptoms will be pretty familiar for example many cancers are associated with weight loss and muscle wasting the term for this is anorexia cachexia and that refers to weakness and body wasting that is due to a chronic disease although cancer treatments can make people nauseous and and diminish their appetite the cachexia is way more pronounced than could be accounted for by diminished calorie intake it's believed to be predominantly related to the hyper metabolic state it takes a lot of energy for the rapid cellular division of tumor cells circulating cytokines are also thought to play a role cancer disrupts tissue integrity tumors cause local tissue compression and erosion of blood vessels one of the first symptoms of colorectal cancer is blood in the stools anemia is also common and might be related to blood loss it also is likely related to impaired red blood cell production or could even be a an effect of the cancer treatment people with cancer also experience fatigue and sleep disturbances sometimes cancer cells actually produce extract hormones or they cause endocrine glands to over secrete hormones for example in some types of lung cancers there is an over excretion of adrenal corticotropic hormone acth in this perineoplastic syndrome patients develop cushing's syndrome we'll talk more about cushing's in a later chapter but generally people with cushing's have abdominal obesity and thin arms and legs cancer is diagnosed by cytocytologic studies tissue biopsies or tumor markers an example of a cytologic study is a pap smear cells are scraped from the cervix they're plated on a slide and a pathologist views the slide to see if they can find any abnormal cells there are many examples of tissue biopsies for example if a mass shows up on a chest x-ray the patient may go have a needle inserted into the mass to aspirate cells and then again the pathologist would view those cells to provide a diagnosis there are several tumor markers that are used to diagnose cancer but these tumor markers can also be used to follow cancer progression or response to treatment patients with prostate cancer will have blood tests to determine the level of their prostate specific antigen or psa men ages 40 to 49 should get a psa at a baseline and if the levels are elevated subsequently then a biopsy would be performed and lastly we're going to talk briefly about this micro array technology or using gene chips to diagnose cancers and to guide therapies in microarray technology cells from the tumor cell tumor cells are used and breast cancer was the first type of cancer to be extensively studied using this technology not only has it helped us better understand the many different differences in breast cancer between one person and another it also provides a lot of prognostic and predictive information such as who would benefit from chemotherapy after surgery this slide lists several tumor markers usually tumor markers are found in the blood but they also may be in urine or body tissues if people are being treated for cancer again decreases in their tumor markers tell us that the treatments are likely working tumor grading tumors are graded on a scale of one to four and this is based on their differentiation and the number of mitoses number one grade one tumor is well differentiated where grade four tumor is poorly differentiated tumors are staged with regard to the tumor itself its lymph the lymph node involvement and metastasis so that's the t n m staging you do need to know the tmn tnm staging classification system for the exam there are three major modalities used to treat cancer surgery radiation and chemo in surgery the tumor and the surrounding area tissue is removed radiation therapy involves using ionizing radiation to kill tumor cells and shrink or eradicate them and surgery often surgery and radiation can be used together maybe the patient will have radiation therapy first and then have surgery to resect any remaining tumor the radiation therapy would be given to shrink the tumor chemotherapy provides a systemic approach so you can kind of see that direct surgery and radiation would be working more locally chemotherapy targets any rapidly growing cell in the body the drugs that are used usually target a specific stage of the cell cycle and multiple drugs are commonly used since both radiation and chemotherapy kill rapidly dividing cells this explains why people lose their hair with these cancer treatments hormone and anti-hormone therapy are specific types of pharmacotherapy used to treat cancers for example in estrogen-positive breast cancer women take the estrogen blocking drugs to prevent tumor growth there are also new biotherapies and targeted therapies that use monoclonal antibodies to tag cancer cells and label them for destruction so the antibody actually draws our natural killer cells from our own immune system to kill the cancer cell childhood cancers luckily are relatively rare they account for about one percent of the cancers in our country and the survival rate for childhood cancer is about 85 percent if kids get cancer it's generally within the first few years of their life and childhood cancers are typically blood and bone marrow cancers like leukemia some warning signs of possible childhood cancers include a prolonged fever fatigue and bone pain persistent enlarged lymph nodes unexplained weight loss and a growing mass that concludes this discussion of part two chapter six so please let me know if you have questions