Cancer

 Anaplasia- lack of cell differentiation in malignant cancerous tissues. Not only do the cells vary in size and shape, but the nuclei are varied as well. (usually exceedingly large.)The tumor resembles its original source (such as if it is resembles the tissues of the liver) the lower the grade of the tumor. The more it morphs from its original source the higher the grade of tumor. **Why are they so dangerous??** According to cancer guest speaker, the more the cells morph the harder it is for the immune system to detect them as foreign invaders. So WBC’s and phagocytes don’t even recognize them and will not actively try to destroy them. Another reason they are prolific is that they can acquire abilities to destroy bacteria. Also, most cancer cells do not have typical apoptosis. Because cancer cells grow rapidly and are larger in size, they play king-of-the-hill w/ the normal WBC’s, erythrocytes, platelets, etc, thus hindering the growth of the “good” cells and crowding them out. These cells grow into smaller and more immature WBC’s. This means that they are ineffective at destroy cancer cells and fighting infection. Much like what happens w/ the left shift. They are also not well versed on contact inhibition. Cessation normally occurs when cells come into contact w/ one another. Cancer cells lack cohesiveness and adhesiveness so they disregard contact inhibition. Instead the go hog wild and grow rampantly through out the body.  Metastasis is when the cancer develops into a secondary tumor in a location distant from the primary tumor. Metastasis occurs in the lymph and blood vessels. The tumor gets wedged in a lymph duct and often die due to lack of a proper environment. However, some cells can break off the tumor and travel through the lymph and into the venous system, spreading the cancer through out the body.
 * Cell Characteristics || Benign || Malignant ||
 * Cell characteristics || Well-differentiated cells that resemble cells in the tissue of origin || Cells that are undifferentiated, with anaplasia and atypical structure that often bears resemblance to cells in the tissue or origin. ||
 * Rate of growth || Usually progressive and slow. My regress or come to a standstill. || Variable and depends on level of differentiation; the more anaplastic the cells, the more rapid the rate of growth. ||
 * Mode of growth || Grows by expansion w/out invading the surrounding tissues; usually encapsulated. || Grows by invasion; sending out processes that infiltrate the surrounding tissues. ||
 * Metastasis || Doesn’t spread to metastasis. || Gain access to blood and lymph channels to metastasize to other areas of the body. ||

2. Describe the agents & mechanisms of action for chemotherapy, immunotherapy, biological response modifies (Porth pgs 98-101. This overlaps with the prototype drugs from this section of Pharmacology)- COLLEEN   **//b.//** __**//Chemotherapy Agents://**__  **Cancer chemotherapy **  is a systemic treatment that enables drugs to reach the site of the tumor as well as the distant sites. It can be the primary or part of a multimodal tx plan. It is the primary tx for hematologic and some solid tumors, including testicular cancer, acute and chronic leukemia, burkitt lymphoma, hodgkin’s dx, and multiple myeloma. Most cancer drugs are designed to destroy cells that are rapidly replicating or in the phase G0 of the cell cycle. According to the cancer lecture guy the reason that people need repeated rounds of chemo is because the cells in the body are not all simultaneously in the G0 cycle at the same time. So, it is more effective to do it multiple times to ensure that you are killing off as many cancer cells as possible. The relationship between tumor cells survival and drug dose is exponential. The number of survivors is proportional to drug dose and the number of cells surviving proportional to drug dose. This means that a percentage of cells are killed rather than a number of cells. Thus, each round of chemo kills another percentage of cells until the amount equals 0. The way that methotrexate works is by interfering with the S phase of the cell cycle. This interrupts the DNA replication part of the cell cycle. You can have cell specific and non-specific drugs. Cell-specific work on a particular phase of the cell cycle. Non-specific drugs work on the cell during the resting phase, rather than the replicating phase. Combinations can be used to attack the cells in different phases. Two well-known combinations are CHOP-cyclophosphamide, doxorubicin, oncovin, and prednisone, which is used to tx Hodgkin’s dx. CMF is cyclophosphamide, methotrexate, 5-fluorouracil, use to tx breast cancer.
 * //i. methotrexate//**
 * methotrexate (//Folex, Rheumatrex//) || Dosage varies with route and disease being treated; 15–30 mg P0 or IM is common || Treatment of leukemias, psoriasis, rheumatoid arthritis, and choriocarcinomas
 * Special considerations:** Hypersensitivity reactions can be severe; liver toxicity and GI complications are common; monitor for bone marrow suppression and increased susceptibility to infections; dose pack available for the oral treatment of psoriasis and rheumatoid arthritis ||

**Immunotherapy **  **Active ** **- ** this is when something like BCG, which is an attenuated strain of bacterium that causes bovine TB is instilled into the bladder. The immune system fights it off and actually ends up kills superficial bladder cancer cells in the process.

**Passive or adoptive immunotherapy ** **- **  transfer of cultured immune cells into a tumor-bearing host.

**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">Biologic Response Modifiers ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;"> **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">Cytokines- ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;"> interferons and interleukins.

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<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">Interferons assist the immune response by inhibiting [|viral replication] within host cells, activating [|natural killer cells] and [|macrophages], increasing [|antigen presentation] to [|T lymphocytes], and increasing the resistance of host cells to viral infection. There are 3 known classes of interferons; type I, type II and type III. All classes are very important in fighting viral infections. They can also prolong the cell cycle and increase the percentage of cells in the G0 phase. ======

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<span style="-webkit-background-clip: initial; -webkit-background-origin: initial; background-color: aqua;">**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">Interleukins ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">- enable communication between cells by binding to receptor sites on cell surface membranes of target cells. There are 18 types. IL-2 is being used for tx of metastatic renal cell carcinoma and metastic melanoma. ====== <span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">

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<span style="-webkit-background-clip: initial; -webkit-background-origin: initial; background-color: aqua;">**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">Monoclonal antibodies ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">-re [|monospecific antibodies] that are identical because they are produced by one type of [|immune cell] that are all [|clones] of a single parent cell. Given almost any substance, it is possible to create monoclonal antibodies that specifically bind to that substance; they can then serve to detect or purify that substance. For cancer, they are combined w/ a toxin, chemotherapy drug or radioisotope to increase effectiveness. ======

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**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">Hematrophic growth factors ** **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">- ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 8.8pt;">growth and maturation factors that include colony-stim factors (CSF’s) These control the production of granulocytes and macrophages, erythrocytes, and platelets. ======