Neoplasia (AKA Cancer) Flashcards
Cell Cycle
orderly sequence - duplicated chromosomes resulting in cell proliferation
Body Tissue:
continuously dividing tissue:
cells divide, replicate in life ex. skin, oral cavity, vagina…generate after injury as long as we have stem cells
Stable tissue: Cells that stop dividing, but undergo regeneration in response to stimuli Ex: solid organs like liver or kidney
permanent tissue:
no further regeneration at all ex: nerve cells, muscle cells, cardiac cells (when they die, they die forever) replaced with scar tissue.
Proliferation
process of increasing cell numbers thru mitotic division
triggered by growth factors , hormone and cytokines.
ex: erythropoetien, stimulating factor
proliferation is the mechanism for replacement when old cells die and additional cells are needed
Differentiation
Process when structure and function of cell becomes SPECIALIZED
new cells acquire characteristics of cells they replace
ex: granulocytes, agranulocytes, platelets, erythrocytes
stem cells are UNDIFFERENTIATED cells that differentiate based on need in continuously dividing tissues
Stem Cell Division
self renewal > asymmetric replication> differentiation
see pic on slide
Apoptosis
Programmed CELL DEATH
IN HEALTH - rate of cell death = rate of cell life
occurs in multiceullular organisms
keeps the number of total cell sin constant health
Neoplasia
occurs when: cell differentiation and growth are NOT regulated
Hypertrophy: enlargement or overgrowth of an organ due to increase in the SIZE of the cells
Hyperplasia: an abnormal multiplication or increase in NUMBER of normal cells of a body part
Neoplasia: Process of formation or presence of a NEW abnormal growth of tissue that is not under physiologic control
Neoplasm: New growth, swelling that is caused by different etiologic factors (AKA TUMOR - benign or malignant)
Neoplasia Pt II
proliferation to form new growth
cells do not die off, to keep the number of total cells constant
benign: well differentiated
malignant: less differentiated (CANCER - cells often do not mature normally to do the “job” the tissue is supposed to do)
Benign Tumors
contain cells that look like normal tissue cell
perform normal function of tissue ex: secrete hormones, but may lead to over secretion
grow slowly
surround by a fibrous capsule
do not infiltrate, invade or metastasize
can damage nearby organs by compressing them
Generally NOT dangerous and can be removed easily
Malignant Tumors
contain cells that do NOT look like normal adult cells
do NOT perform normal functions of the tissue
may secrete signals, enzymes, toxins ect…
grow rapidly
infiltrate, invade, metastasize (to distant sites)
can compress and/or destroy the surrounding tissues
Cancer Incidence
leading types (not on test)
Men - prostate, lung, colon, rectum, bladder, melanoma
Women - Breast, lung, colon, rectum, uterine, thyroid
Most deaths from LUNGS, breast and colon
Tumor Types
Solid tumors:
initially confined to specific tissue or organ but then detach and invade surrounding tissue, blood and lymph (then it gets worse)
Hematologic cancer:
Blood and lymph contain the cancer cells INITIALLY. These cancers are considered disseminated diseases from the beginning
Cancer in Situ:
Cancer cells that are localized in the organ of origin. Considered PRE-INVASIVE lesions, they can be surgically removed or treated more easily and have a smaller chance of recurrence
Tumor Cell Characteristics
Poorly differentiated or non-differentiated tumor cells are described as ANAPLASTIC cells
cells contain numerous morphologic changes and vary in size and shape (PLEOMORPHISM)
cells have high rate of proliferation, do not resemble tissue of origin
Grading of tumors is based on how differentiated the cells are and the number of proliferating cells: Range from I-IV
Grade I are well differentiated
Grade IV are identified as anaplasia
Cells and -Plasia
Hypoplasia - too few cells that deemed normal (ex. under developed breasts, benign)
Hyperplasia - increase number of cells than normal, result of external stimuli (think of callus on skin after trauma)
Neoplasia - similar to hyperplasia, but denotes ABNORMAL multiplication due to loss of normal proliferation regulation
Dysplasia - change in the normal shape and size and organization of cell, usually bc of CHRONIC irritation (ex. smoking)
Metaplasia - Change in cell type. ex. lung epithelium to squamous after prolonged smoking
Anaplasia - reversal in differentiation OR loss of structure and function of cell. Ex. cancerous tumors
Genetic Instability
HALLMARK OF CANCER
Defined as presence of high frequency of mutation fo cells that change sequences of nucleic acid and arrangement of chromosome
growth regulatory genes and genes involved in cell cycle progression are ALTERED or arrested, resulting in gross chromosomal abnormalities
end result is ANEUPLOIDY - an incorrect number of chromosomes
Growth properties: Cancer VS Normal cells
some cancers secrete growth factors and/or have receptors
ex. breast cancer cells - no estrogen receptor cells
Normal cells have a cell density dependent on inhibition. Ex. wound healing, when cells contact (contact inhibition) the cells respond and stop growing, but with CANCER, they KEEP growing (aka lack inhibition)
Cancer cells do not stick together and shed into surrounding body fluids.
cancer cells have anchorage independence
Anoikis - healthy cell apoptosis
cancer cells: faulty cell to cell communication also immortal (never die)
