Lecture Notes: Cancer Pathology and Treatment

Flashcards covering key vocabulary, definitions, classifications, mechanisms, and treatments related to cancer from lecture notes.

Malignant Tumor

An abnormal growth resulting from uncontrolled proliferation that serves no physiologic function, also referred to as a neoplasm or cancer.

Neoplasm

Another term for a new growth, often referring to a tumor.

Benign Tumor

Characterized by slow growth, usually a well-defined capsule, non-invasive, low mitotic index, and does not metastasize.

Malignant Tumor Characteristics

Characterized by rapid growth, not encapsulated, invasive, poor differentiation (anaplasia), high mitotic index, and ability to spread to distant sites.

-oma

Suffix used to designate benign tumors, e.g., lipoma (fatty tumor), leiomyoma (smooth muscle tumor).

Carcinomas

Malignant epithelial tumors.

Adenocarcinoma

Malignant tumors of ducts or glands.

Sarcomas

Malignant connective tissue tumors.

Lymphomas

Cancers of lymphatic tissues.

Leukemias

Cancers of blood-forming cells.

Carcinoma in Situ (CIS)

Pre-invasive epithelial malignant tumors of glandular or squamous origin that have not broken through their basement membrane or invaded surrounding stroma.

Clonal Proliferation and Expansion

The process by which a cell acquires characteristics (due to mutation) that allow it to have a selective advantage over its neighbors, leading to increased growth rate or decreased apoptosis in cancer.

Mutation

An alteration in a DNA sequence affecting expression or gene function, a prerequisite for cancer development.

Point Mutations

Small-scale changes or driving mutations that propel the progression of cancer.

Passenger Mutations

Random mutations that do not directly drive cancer progression.

Gene Amplification

Repeated duplications of a chromosome segment, leading to tens to hundreds of gene copies that amplify a specific gene.

Chromosome Translocation

A change to the chromosome structure where a piece of one chromosome is translocated to another chromosome.

Malignant Transformation

The process through which a normal cell becomes a cancer cell, resulting in a heterogeneous mixture of cancer cells within their stroma.

Tumor Microenvironment (Stroma)

The heterogeneous mixture of cancer cells and surrounding supporter cells and extracellular matrix within a solid tumor, resembling a non-healing wound.

Oncogenes

Mutant genes that, in their non-mutant state (proto-oncogenes), directed protein synthesis and cellular growth, but now promote uncontrolled growth.

Proto-oncogenes

Normal, non-mutant genes that code for cellular growth, becoming oncogenes when mutated.

Tumor Suppressor Genes

Genes that encode proteins that, in their normal state, negatively regulate proliferation, also known as anti-oncogenes. Mutation or loss leads to uncontrolled growth.

Autocrine Stimulation

Cancer cells secrete growth factors to stimulate their own growth.

TP53 Gene

A tumor suppressor gene that, when mutated, suppresses normal apoptosis, allowing continued growth of tumors.

Caretaker Genes

Genes responsible for maintaining the genomic integrity by encoding proteins involved in repairing damaged DNA; their loss increases mutation rates and cell proliferation.

Genomic Instability

The increased tendency of alterations in the genome during cell divisions, driven by epigenetic silencing, mutations in caretaker genes, and chromosome instability.

Chromosome Instability (CIN)

Increased in malignant cells, potentially caused by malfunctions in cellular machinery regulating chromosomal segregation at mitosis, leading to loss of tumor suppressor genes and overexpression of oncogenes.

miRNA (miR)

Small non-coding RNA molecules that regulate gene expression networks. Changes can lead to 'onco-miRs' that stimulate cancer.

Hayflick Limit

The finite number of times normal body cells can divide before undergoing apoptosis or senescence.

Telomeres

Protective caps on each chromosome that shorten with each cell division; their activation in cancer cells allows continued division.

Telomerase

An enzyme that maintains and rebuilds telomeres, often active in cancer cells, allowing them to bypass the Hayflick limit.

Angiogenesis (Neovascularization)

The process by which cancer cells grow new blood vessels to supply the tumor with nutrients and oxygen, facilitated by angiogenic factors.

Vascular Endothelial Growth Factors (VEGF) and Basic Fibroblast Growth Factors (bFGF)

Angiogenic factors secreted by advanced cancers to facilitate the growth of new blood vessels.

Reverse Warburg Effect

Describes the efficient metabolism of cancer cells, utilizing glycolysis to produce lactic acid and metabolites for rapid cell growth and ATP generation.

Inflammation and Cancer

Chronic inflammation is a significant risk factor for cancer, stimulating wound healing responses including proliferation and angiogenesis.

Tumor Associated Macrophages (TAMs)

Macrophages that are key promoters of tumor survival, blocking cytotoxic T-cells and natural killer cell functions, producing pro-tumor cytokines, and secreting angiogenesis factors.

Immune Surveillance Hypothesis

A theory stating that the immune system constantly monitors the body for tumor cells and destroys most aberrant cells before they develop into clinically manifest tumors.

Immunotherapy

A treatment strategy for disease, including cancer, by activating or suppressing the body's immune system.

Active Immunotherapy

Immunization with tumor antigens to elicit or enhance an immune response against a particular cancer.

Passive Immunotherapy

Injecting a patient with antibodies or lymphocytes directed against tumor-associated antigens.

Metastasis

The spread of cancer cells from the site of the original tumor to distant tissues and organs through the body.

Invasion

The local spread of cancer, a prerequisite for metastasis and the first step in the metastatic process.

Protease

Enzymes secreted by cancer cells that digest the extracellular matrix and basement membranes, creating pathways for cell movement.

Epithelial-Mesenchymal Transition (EMT)

A process where epithelial-like characteristics (polarity, adhesion) are lost, increasing migratory capacity, resistance to apoptosis, and dedifferentiation to a stem-cell like state in metastatic cells.

Paraneoplastic Syndromes

Symptom complexes triggered by cancer, but not directly caused by the local effects of the tumor, often due to substances released by the tumor or an immune response.

Cachexia

The most severe form of malnutrition associated with cancer, leading to protein-calorie malnutrition, progressive wasting, anorexia, and altered metabolism.

Cancer Staging (Stage 1-4)

A system to classify cancer extent: Stage 1 = confined to organ of origin; Stage 2 = locally invasive; Stage 3 = advanced to regional structures; Stage 4 = spread to distant sites.

TNM System

A more detailed staging system: T for Tumor (size/invasion), N for Nodes (lymph node involvement), M for Metastases (distant spread).

Tumor Markers

Substances produced by benign or malignant cells found in blood, spinal fluid, or urine; used for screening, diagnosis, and monitoring treatment response.

Alpha-Fetoprotein (AFP)

A protein secreted by liver and germ cell tumors, used as a tumor marker.

Prostate-Specific Antigen (PSA)

An antigen secreted by prostate tumors, used as a tumor marker.

Induction Chemotherapy

Chemotherapy administered to cause shrinking or disappearance of tumors.

Adjuvant Chemotherapy

Chemotherapy given after surgical excision to eliminate any micro-metastases.

Neo-Adjuvant Chemotherapy

Chemotherapy administered before surgical or radiation treatment to shrink tumors and improve the effectiveness of subsequent treatments.

Childhood Cancers

Most commonly central nervous system tumors and leukemias (in early childhood) or lymphomas and sarcomas (in adolescence); often originate from mesodermal germ layer.

Embryonic Tumors

Childhood cancers originating during intrauterine life from immature embryonic tissue, often named with the suffix '-blast'.

DES (Diethylstilbestrol)

A drug used prenatally to promote pregnancy, found to increase cancer risk in subsequent generations.