Neoplasia Flashcards
Incidence
Number of people who develop the disorder
Mortality
Number of people who die from the disorder
Neoplasm
New growth
Proliferation
Process of cell division
Differentiation
Specialization of cells
Regulated by genes and environment
Rely on progenitor cells (cells in earlier stage of differentiation)
Maturity
Differentiated cells having reached full functional potential
Stem cells
Properties: - Self-renewal - Potency Divide into: - Daughter cell - Stem cell
-oma suffix
- Benign
- Preceded by name of tissue origin
-carcinoma suffix
- Malignant neoplasm of epithelial tissue
-sarcoma suffix
- Malignant neoplasm of mesenchymal cells
Benign tumors
- Well differentiated, resemble tissue of origin
- Slow growth
- Grow by expansion, usually encapsulated
- No metastasis
- Low potential for death
Malignant tumors
- Poorly differentiated, little resemblance to tissue of origin
- Variable rate of growth; the more undifferentiated, the more rapid
- Grows by invasion
- Will spread with access to blood and lymph channels
- High potential for death
Solid tumors
- Category of malignant neoplasm
- Confined to tissue or organ
- Cells detach and invade surrounding tissue
- Very fragile
- Cells can fall off and create cancer (seeding)
Hematologic cancers
- Category of malignant neoplasm
- Involve cells already in circulation
Carcinoma in situ
- Localized, pre-invasive lesion
- Lesion that has not spread
Cancer cell characteristics
- Abnormal, rapid proliferation
- Loss of differentiation - anaplasia - no normal features of differentiated cells
- Genetic instability
- Growth factor independence
- Cell density - dependent inhibition
- Loss of cell cohesiveness and adhesion
- Do not require anchorage to neighboring cells to develop
- Cell-to-cell communication is lost
- Immortal life span
- Produce antigens immunologically different than host
- Produce enzymes, hormones, etc
- Cytoskeletal changes
Loss of differentiation in cancer cells
- Cells and nuclei variable in shape (pleiomorphic)
- Clumped chromatin
- Large nucleoli
- Neoplasms with cells in various stages of mitosis
- Mitosis is abnormal
- Grade I to IV
Genetic instability in cancer cells
- Inherent stability that contributes to development and progression of cancer
Growth factor independence in cancer cells
- Ability to proliferate without growth factor
Cell density in cancer cells
- Dependent inhibition
- Cessation of growth when cells reach a pre-determined density
Paraneoplastic syndrome
Ability of cancer to produce hormones made in another part of the body
Can continue secreting despite feedback mechanisms
Cancer spread
Direct invasion - Direct extension - Seeding Metastasis - Blood - hepatic portal vein - Lymph - sentinel node
Angiogenesis
Creation of new blood vessels
- Outer rim usually has better blood supply
- Center of cancer often becomes ischemic and necrotic
Cancer growth
Continue to divide until limits in blood supply and nutrients affect it
Double time - time taken for a tumor to double in size
Etiology
Genetic basis - originate due to genetic damage or mutation
Under-activity or silencing of normal regulatory genes or overactivity of proto-oncogenes
Evasion of apoptosis
Evasion of cellular senescence
Development of sustained angiogenesis
Invasion and metastasis
Proto-oncogenes
Code for growth factors, growth factor receptors, transcription factors, etc
Overactivity can promote cancer
Tumor suppressor genes
Under-activity can interfere with normal processes
Cancerous cells not eliminated and are allowed to grow
Ex: BRCA gene
Cancer causes related to host
Heredity - Genetic predisposition Hormones - Mechanism is unclear Immunology - Impaired ability to suppress tumor growth (immunocompromised, elderly_
Cancer causes related to environment
Chemical carcinogens
Radiation (ionizing, ultraviolet)
Viruses (HPV, EBV, HBV, HHV-8)
Bacteria (H. pylori)
Systemic symptoms of cancer
Anorexia-cachexia
Fatigue
Cancer-induced anemia
Nutritional deficiency
Bone marrow failure
- Fast growing cancers can cause crowding
Inflammatory cytokines
- Body’s attempt to remove tumor can interfere with ability to create RBC
Paraneoplastic syndromes
Cancer producing manifestation in sites not affected by primary cancer
Can be due to hormones or other chemicals released by neoplasm
Benign and malignant tumors
Most common in lung, breast, and hematologic cancers
SIADH
Paraneoplastic syndrome
Syndrome of increased ADH by a tumor
Cushing syndrome
Paraneoplastic syndrome
Elevated cortisol from tumor that secretes ACTH
Hypercalcemia
Paraneoplastic syndrome
Cancer secretes peptide similar to PTH
Venous thrombosis
Paraneoplastic syndrome
Cancer secretes procoagulation factors
Acanthosis nigricans
Paraneoplastic syndrome
Skin changes
Possible due to epidermal growth factors from cancer
Modes of cancer treatment
Radiation
- Destroy/damage cells by creating free radicals
- Rapidly proliferating cancer cells are more susceptible
Chemotherapy
- Prevent cell growth
Inhibit DNA, RNA, protein synthesis
Hormone therapy
- Disrupt hormonal environment of cancer cells
Biotherapy
- Change person’s immune response to cancer
