Neoplasia/Oncology Fall 2024-2025 NURS 210A PDF

Neoplasia/Oncology MAR INA GH AR IBI AN PHD R N NURS 210A FALL 2024-2025  Neoplasia (new growth). Cancer is a disorder of altered cell differentiation and growth; Cancer cells escape the normal regulatory processes that regulate cell growth and division. Cancer Abnormal...

Neoplasia/Oncology MAR INA GH AR IBI AN PHD R N NURS 210A FALL 2024-2025  Neoplasia (new growth). Cancer is a disorder of altered cell differentiation and growth; Cancer cells escape the normal regulatory processes that regulate cell growth and division. Cancer Abnormal Proliferation Metastasis cell growth Types of Cancer Three basic categories Sarcomas: These are Carcinomas: These are Blood-based cancers:: cancers of connective tissue cancers that begin in These include such as bone, blood vessels, epithelial cells that line the leukemias, lymphomas, cartilage, and nerves. surface of the body or body cavities (skin, breast). and multiple myeloma. They make up the largest group of cancers  "Onco" means mass, and "logy" means study, Oncology: Oncology is the field of medicine that deals with the diagnosis, treatment, prevention and early detection of Cancer. Oncologists, are physicians who treat people with cancer. Terminology Tumor: a mass that arises because of overgrowth Anaplasia: a condition whereby cells divide rapidly and do not resemble normal cells neither in structure nor in function. Cancer is currently the second leading cause of death in the United States  Neoplasms are classified as benign or malignant Benign tumors are not life threatening unless their location impairs the function of vital organs. Benign or Tumors are named by adding suffix –oma and are classified and named depending on the type of tissue Malignant? affected The term carcinoma is used to designate malignant neoplasms For example, a benign tumor of glandular epithelial tissue is called adenoma whereas a malignant one is called…??? In normal tissues, the rates of new cell growth and old cell death are kept in balance. uncontrolled cell growth or Disruption of balance loss of a cell's ability to Cancer undergo apoptosis Cancer Cell Division Benign and Malignant Neoplasms  Benign versus Malignant Cell Characteristics Benign Malignant Cell characteristics Well differentiated that Undifferentiated with anaplasia and resembles the cells in the tissue atypical structure that rarely of origin resembles the cells in the tissue of origin Rate of growth Slow growing Rapid growing, especially if undifferentiated Mode of growth Expands but does not invade Invades and infiltrates surrounding other organs usually tissues encapsulated Metastasis Does not metastasize Gains access to lymph and blood vessels and spreads to other organs  Levels of differentiation Well differentiated: A term used to describe cells and tissue that have mature (specialized) structures and functions. In cancer, well-differentiated cancer cells tend to grow and spread more slowly than poorly differentiated or undifferentiated cancer cells. Well-differentiated: These tumor cells look very similar to normal, healthy cells but they still behave in a manner that makes them a cancer. Moderately differentiated: These tumor cells are abnormal-looking but still share some features with normal, healthy cells. Poorly differentiated: These tumors cells look very little like normal, healthy cells. Undifferentiated: These tumor cells look and behave nothing like normal, healthy cells.  Cell Markers A 'Cell Marker' is a molecule (proteins or carbohydrates) that is linked to the function of a cell, These markers are found on the surface of cells and can be used to determine the stage of development, maturity, or activation of a cell. They act like a "fingerprint" to identify specific cell types and can be used to identify different types of cells such as cancer cells, stem cells, and cells infected with HIV. An example is the expression of Insulin, which confirms the β-cell identity; In the immune system, "Cluster of Differentiation" (CD) molecules are commonly used as cell surface markers to identify different immune cell populations. They are used to study cell development, identify cancer cells, and understand cell-cell interactions. Cell Markers Nucleolus Markers Nuclear Markers Ribosomal Markers Endoplasmic Reticulum Markers Golgi Apparatus Markers Mitochondrial Markers Cytoplasm Markers Lysosome Markers Plasma Membrane Markers  Cell surface markers and correlating immune cell type Currently, the most common cell surface Surface Present on markers are CD molecules and clusters Marker of differentiation. CD molecules are CD3 T lymphocyte surface molecules expressed on cells of the immune system that play key roles in CD4 T helper cell immune cell-cell communication and CD11b Monocytes, Macrophages, dendritic sensing the microenvironment. These cells, mast cells molecules are essential markers for the CD16 Monocytes, Neutrophils identification and isolation of leukocytes and lymphocyte subsets. CD19 B cells  Structure of cancer cells The nuclear structure of cancer cells undergoes changes that result in a large, irregularly shaped nucleus and modifications to the chromosomes. These morphological characteristics have been considered the “gold-standard” for diagnosing cancer. In general, normal cells have a regular and ellipsoid shape while cancer cells are often irregular. The size of the ER and mitochondria decreases, and the Golgi apparatus is underdeveloped. Normal cells vs. Cancer cells Cancer cell dividing  T lymphocytes trying to attack cancer cell Cancer cell A tumor is forming  Contact inhibition Normal cells will only divide a few times before arresting. They grow as a uniform layer of cells with many tight connections between neighboring cells. They will divide until they are in contact with the neighboring cells, at which point they stop growing. This results in a sheet of cells just one layer thick. Contact inhibition Contact inhibition is a regulatory mechanism that functions to keep cells growing into a layer one cell thick (a monolayer). If a cell has plenty of available substrate space, it replicates rapidly and moves freely. This process continues until the cells occupy the entire substratum (the underlying support). At this point, normal cells will stop replicating. Cancerous cells typically lose this property and thus divide and grow over each other in an uncontrolled manner even when in contact with neighboring cells. This results in the invasion of surrounding tissues, their metastasis to nearby organs, and eventually tumorigenesis. Nonmalignant tissue vs. tumor tissue A cancer-associated fibroblast (CAF) is a cell type within the tumor microenvironment that promotes the remodeling of the extracellular matrix.  Defects in DNA repair mechanisms: genetic damages that causes this condition may be related to the action of chemicals, radiation, viruses, or are inherited Defects in growth factor signaling pathways: a common way in which cancer cells gain autonomous growth is through mutations in genes that control growth factor Molecular and signaling pathways Cellular Prevention of apoptosis: cancer cells fail to undergo Pathways apoptosis due to alteration in cell survival signaling >>> immortality of cancer cells Prevention of cellular aging (senescence): cancer cells are immortal due to presence of telomerase, an enzyme that adds DNA sequence repeats, thus preventing cell aging Development of sustained angiogenesis: tumors develop their own blood supply  Telomerase On the end of our chromosomes is a structure known as a telomere. Every time a cell divides, its telomeres become shorter. When the telomeres become short enough, the cells die. Cancer cells have figured out a way to restore their telomeres so that they don’t continue to shorten as the cell divides, making them immortal. Telomerase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes. Telomerase is found in fetal tissues, adult germ cells, and also tumor cells. Telomerase-the “immortality enzyme” Telomerase: an enzyme that adds nucleotides to telomeres, especially in cancer cells. Telomerase uniquely holds the key to delaying or even reversing the cellular aging process. The activation of telomerase in malignant cancers seems to be an important step in tumorigenesis, which gives the cell the ability of indefinite proliferation to become immortal. Invasion and Metastasis Invasion Metastasis Seeding Direct migration Ability of cancer Cancer spread in and penetration by cells to: body cavities cancer cells into  penetrate neighboring tissues lymphatic and blood vessels  circulate through the bloodstream  invade other tissues Invasion and Metastasis  Metastasis occurs through:  Lymph channels (sentinel node) and  Blood vessels. The sentinel nodes are the first few lymph nodes into which a tumor drains from the primary tumor. They are the first place that cancer is likely to spread. Pathogenesis of In breast cancer, the sentinel node is usually located in the Metastasis axillary nodes, under the arm. When cancer spreads, the cancer cells may appear first in the sentinel node before spreading to other lymph nodes. (melanoma and breast cancer) Unfortunately, a metastatic tumor can be found far advanced before the primary tumor becomes clinically detectable  a: Cellular transformation and tumor The pathogenesis of cancer growth. metastasis b: Vascularization c: Local invasion of the host stroma by some tumor cells by several mechanisms. Thin-walled venules, such as lymphatic channels, offer very little resistance to penetration by tumor cells and provide the most common route for tumor-cell entry into the circulation. d: Detachment and embolization of single tumor cells occurs next, After the tumor cells have survived the circulation, they become trapped in the capillary beds of distant organs by adhering to capillary endothelial cells. e: Extravasation occurs next — probably by mechanisms like those that operate during invasion. The five key steps of metastasis Invasion, Intravasation, Circulation, Extravasation, Colonization Cancer cell breaks loose from the primary tumor Invades the surrounding extracellular matrix Gains access to a blood vessel Survives its passage into the bloodstream Emerges from the bloodstream at a favorable location Invades the surrounding tissue Begins to grow in the tissue  Pathophysiology of Cancer Metastasis occurs Protoncogenes when abnormal change to Cell grows and cells invade other oncogenes proliferates tissues through because of DNA lymph and blood mutation vessels  Promotion: Initiation: cell unregulated, exposure to doses of accelerated growth carcinogens makes in already initiated them susceptible to Steps Involving malignant cells caused by various chemicals the transformation. and growth factors Transformation of Normal Cells Progression: Tumor Into Cancer cells acquire Cells malignant changes that promote invasiveness, metastatic competence and autonomous growth tendencies. Carcinogenesis Phases  Grading of Tumors Involves the microscopic examination of cancer cells to determine their level of differentiation and the number of mitosis. Ranges from I to IV The higher the anaplasia the higher the grade The lower the differentiation the higher the grade  Staging of Tumors There are many staging systems. Some, such as the TNM staging system, are used for many types of cancer. Others are specific to a particular type of cancer. Most staging systems include information about: Where the tumor is located in the body The cell type (such as, adenocarcinoma or squamous cell carcinoma) The size of the tumor Whether the cancer has spread to nearby lymph nodes Whether the cancer has spread to a different part of the body Tumor grade, which refers to how abnormal the cancer cells look and how likely the tumor is to grow and spread  TNM System When cancer is described by the TNM system, there will be numbers after each letter that give more details about the cancer—for example, T1N0M0 or T3N1M0. The following explains what the letters and numbers mean: Primary tumor (T) TX: Main tumor cannot be measured. T0: Main tumor cannot be found. T1, T2, T3, T4: Refers to the size and/or extent of the main tumor. The higher the number after the T, the larger the tumor or the more it has grown into nearby tissues.  TNM System N: degree of spread to regional lymph nodes ◦Nx: lymph nodes cannot be assessed ◦N0: no regional lymph nodes metastasis ◦N1: regional lymph node metastasis present; at some sites, tumor spread to closest or small number of regional lymph nodes ◦N2: tumor spread to an extent between N1 and N3 (N2 is not used at all sites) ◦N3: tumor spread to more distant or numerous regional lymph nodes (N3 is not used at all sites) M: presence of distant metastasis ◦M0: no distant metastasis ◦M1: metastasis to distant organs (beyond regional lymph nodes) Diagram showing the T stages of bladder cancer  Another staging system In situ—Abnormal cells are present but have not spread to nearby tissue. Localized—Cancer is limited to the place where it started, with no sign that it has spread. Regional—Cancer has spread to nearby lymph nodes, tissues, or organs. Distant—Cancer has spread to distant parts of the body. Unknown—There is not enough information to figure out the stage. Carcinoma in Situ  A final word Cancer is a frightening disease, and emotions can run deep if you hear this word. It can help to know that treatments—and survival rates—for cancer are improving steadily. More than half of people with cancer enjoy long-term survival after their initial diagnosis. At the same time, experts are learning more about the causes and what might be done to prevent cancer in the first place. Research and advances are taking place every day, with hundreds of medications currently being studied in clinical trials. Thank you