Cancer Overview and Terminology

Neoplasia/Oncology Overview

• Neoplasia is the term for new growth
• Cancer is a disorder caused by altered cell differentiation and growth
• Cancer cells bypass the normal regulatory processes for cell growth and division
• This leads to uncontrolled cell growth and proliferation
• Metastasis is the process where cancer cells spread to other locations

Types of Cancer

• Sarcomas: Cancers of connective tissues, such as bone, blood vessels, cartilage, and nerves.
• Carcinomas: Cancers that originate in epithelial cells lining the body or body cavities (e.g., skin, breast). They are the most common type of cancer.
• Blood-based cancers: Cancers like leukemia, lymphoma, and multiple myeloma.

Terminology

• Oncology: The field of medicine dealing with cancer diagnosis, treatment, prevention, and early detection.
• Oncologists: Physicians who treat cancer patients.
• Tumor: A mass that grows due to overgrowth of cells.
• Anaplasia: A condition in which cells rapidly divide but do not resemble normal cells in structure or function (a hallmark characteristic of cancer).
• Cancer is the second leading cause of death in the US.

Benign Tumors vs. Malignant Tumors

• Benign tumors are not life-threatening unless their location harms a vital organ.
• They are named with an "-oma" suffix.
• Benign tumors grow and expand but don't invade or spread to other organs, while malignant do invade and spread.
• Carcinoma refers to a malignant tumor. A benign tumor of glandular tissue is called adenoma, while a malignant one is called a carcinoma.

Factors leading to Cancer

• In normal tissues, new cell growth and old cell death balance each other.
• When this balance is disrupted, uncontrolled cell growth or loss of a cell's ability to undergo apoptosis can lead to cancer.

Cancer Cell Division

• Normal cell division: A damaged cell undergoes apoptosis (programmed cell death) and is replaced by a healthy cell.
• Cancer cell division: Damaged cells reproduce, resulting in uncontrolled cell growth.

Levels of Differentiation

• Well-differentiated: Cancer cells that look and behave similarly to normal cells.
• Moderately differentiated: Cancer cells that are abnormal but still share some characteristics with normal cells.
• Poorly differentiated: Cancer cells which don't look much like normal cells.
• Undifferentiated: Cancer cells that do not resemble normal cells at all.

Cell Markers

• Cell markers: Proteins or carbohydrates on a cell's surface that indicate the cell type, stage of development, maturity, or activation.
• Used to identify specific cell types, such as cancer cells, stem cells, and cells infected by HIV.
• Examples include cell surface markers CD3, CD4, CD11b, CD16, and CD19, used for identifying and categorizing immune cells.
• Other markers can be found in the nucleolus, nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, mitochondria and in the cytoplasm, lysosomes, and plasma membrane.

Cell Surface Markers (Immune System)

• CD molecules (clusters of differentiation) are crucial for immune cell-cell communication and sensing the microenvironment.
• Markers are used to identify and isolate different types of white blood cells (leukocytes) and lymphocytes.

Normal Cells Versus Cancer Cells

• Normal cells exhibit uniform shape and uniformity in size. In contrast, cancer cells show a variation in size and shape.
• Nucleus of normal cells are typically small and uniform, while those in cancer cells are enlarged and often contain multiple nucleoli.
• Normal cells are normally arranged in discrete tissue structures. cancer cells show disorganized arrangement
• Normal cells generally have a high degree of differentiation with specific functions, whereas tumor cells often show a loss of differentiation.

Structure of Cancer Cells

• Cancer cells have irregularly shaped nuclei and altered chromosome structures.
• Size and structure of cell parts like the Endoplasmic Reticulum (ER), mitochondria and the Golgi apparatus are abnormal.

Normal Cells Versus Cancer Cells Summary Diagram (19)

• Normal vs. cancer cell characteristics summarized in a visual diagram. Key differences include cellular characteristics, growth, and arrangement.

Cancer Cell Division Summary Diagram (20 and 21)

• Visual representation of normal and abnormal cell division processes. Cancerous cells divide uncontrollably. Image representing an immune response to attack the cancerous cells

Tumor Formation

• A tumor is a mass of abnormal cells.

Cancer Cell Development (23)

• Normal cell vs. cancer cell development represented through illustrations highlighting the stages of growth and tissue invasion.

Contact Inhibition

• Normal cells stop dividing when they come into contact with other cells, maintaining a single layer. Cancer cells lose contact inhibition. This leads to uncontrolled cell growth.

Metastasis

• Direct migration and penetration of cancer cells into neighboring tissues.
• The ability to invade lymphatic and blood vessels and spread through the bloodstream to other tissues. Spreading cancer cells spread through body cavities.

Invasion and Metastasis - Summary Diagrams (35 and 36)

• Metastasis process visualised; cancer cell invasion of surrounding tissues and blood vessels, travel through the circulatory system, and establishment in new locations. (35) Cancer cell behavior is displayed via diagrammatic progression; benign vs. malignant cells with time.

Pathogenesis of Metastasis (37 and 38)

• The process through which cancer cells spread throughout the body. Includes steps like cellular transformation, vascularization, invasion, embolization, adhesion, and extravasation. Diagrams illustrate this process.

The Five Key Steps of Metastasis (39)

• The five steps in the process: Invasion, Intravasation, Circulation, Extravasation, and Colonization.

Cancer Cell Spread (40)

• Cancer breaks away from the primary tumor, invades the surrounding matrix, enters a blood vessel, survives its journey in the bloodstream, moves to a favorable location, and invades the surrounding tissues.

Pathophysiology of Cancer (41)

• Protoncogenes change to oncogenes due to DNA mutations. This leads to uncontrolled cell growth and proliferation. Tumor spreading through the lymphatic or blood vessels.

Steps Involving the Transformation of Normal Cells into Cancer Cells (42)

• The process of cancer development is separated into initiation, promotion, and progression stages. These are explained with illustrations.

Carcinogenesis Phases (44)

• Initiation, Promotion, Progression, and Metastasis phases in development of cancer illustrated including agents that can increase or decrease these phases.

Initiation, Promotion, Progression (45)

• Process of cell transformation from normal to cancerous cell in diagrams.

Most Common Types of Cancer in US (46)

• The most common cancers in the US (including Breast, Lung, Melanoma, Colorectal, Uterus) and their projected incidence in 2022.

Inside the Cell (47)

• Diagram showing the cell, nucleus, chromosome and DNA, and Gene components.

Tumor Grading (48)

• Grading of tumors is a microscopic examination of cancer cells to determine their level of differentiation and the number of mitotic cells. Grades range from I-IV.

Tumor Staging (49)

• Staging of tumors includes factors such as location, cell type, size, lymph node spread, and distant spread, in order to identify the type of cancer.

TNM System Explained (50 and 51)

• The TNM staging system (Tumor, Node, Metastasis) is used to describe and categorize different types of cancer. There descriptions (TX, T0, T1, T2, T3, T4) and the description of N (lymph nodes spread), degree to distant metastasis.

Diagrams showing the T stages of bladder cancer (52)

• Diagram showing stages T1-T4 of bladder cancer.

Another Staging System (53)

• Different levels of cancer development (in situ, localized, regional, distant, unknown) visualised and described.

Carcinoma in Situ (54)

• A stage of cancer where the abnormal cells have not yet spread outside their initial location.

A final word (55)

• Final statement about cancer research and future advancements.

This quiz provides an overview of neoplasia and oncology, exploring the various types of cancer and key terminology associated with the field. Test your knowledge on how cancer develops, the role of oncologists, and the differences between sarcomas and carcinomas. Dive into the critical concepts that shape our understanding of cancer.