Cancer Flashcards
Benign Cells
differentiated
look like parent cells
they do not invade other tissues or metastasize
well organized and encapsulated
normal cell structure
Malignant (Cancerous) Cells
transformed cells
lack need for growth factors
lack contact inhibition (they won’t stop growing when they come in contact with another cell)
immortal
anchorage independent
faulty cell-cell communication, proliferation
Tumor Growth
Dependent on Three Factors
- the number of cells that are actively dividing or moving through the cell cycle
- the duration of the cell cycle
- the number of cells that are being lost relative to the number of new cells being produced.
Tumor Grading
through microscopic examination of differentiation
I= well differentiated IV= poorly differentiated
Tumar Staging
clinical, radiographic, surgical exaltation of extent and spread (treatment prognosis)
stage 1: confined to organ of origin
stage 2: locally invasive
stage 3: spread to regional lymph
stage 4: distant spread (to the brain)
TNM System for Staging
T: Tumor Size (1-4)
N: Node Involvement (0-3)
M: Metastasis (0-1) (either you have or you haven’t metastasized)
How do you diagnose cancer?
Tumor Markers: antigens expressed on the surface of tumor cells or substances released from normal cells in response to the presence of tumor, in blood, spinal fluid or urine (CEA, PSA, CA-125, CA-19-9)
Cytologic, Histologic and Gene-Profiling Methods:
Papanicolaue Smear (Pap Smear)
Tissue Biopsy
Immunohistochemistry
Microarray Technology
Proto-Oncogenes
gene-overactivity; normal genes that become cancer causing if mutated
Tumor-Suppressor Genes
cancer associated under activity genes, by being less active they create an environment in which cancer is promoted
more active causes suppression of cancer
inhibit mutant cell proliferation
decrease cell division
Angiogenesis
Tumor cells (and other cells) in the microenvironment secrete factors that enable the development of new blood vessels within the tumor
need blood supply for nutrients so they can grow
vascular endothelial growth factor attracts cells from blood vessels to grow within them
they not only are able to feed themselves, but can metastasize through the same blood vessels
Angiogenesis and Metastasis
tumor cells have been show to express functional chemokine receptors
they can sustain cancer cell proliferation, angiogenesis and survival and promote organ-specific localization of metastasis
tumors cannot enlarge unless angiogenesis occurs and supples them with the blood vessels necessary for survival
How Do Cancer Cells Metastasize
cancer cells break off and leave tissue of origin and start new cancer development in distant site via lymphatic/blood vessel systems
Common Sites of Metastasis:
Lungs, Liver, Bones, Lymph Nodes
Risk Factors for Cancer
Age (exposed to more)
Chronic Inflammation (inflamed cells have higher rates of mutation)
Obesity (insulin, IGF-1, hormones, inflammation)
Hormones (breast, ovarian, endometrial, prostate)
Hereditary (BRCA1 and BRCA2 breast cancer)
Immune System Damage (tumor antigens)
Viral/Bacterial (HPV, EBV, Hep B and C)
Chemical Carcinogens
Ionizing Radiation (atomic bomb, UV)
Cervical Cancer Screening
Papanicolaou (Pap) Smear
age: beginning at 21 years old regardless of sexual historians be done every 3 years between the ages of 21 and 29 years.
for women 30-65 years the preferred approach is to be screened every 5 years with the combination HPV and Pap smear cytology.
women who prefer may continue to be screened every 3 years with Pap smear cytology
it is recommended that women discontinue screening after the age of 65 if they have had negative cytology results the previous 10 years.
Breast Cancer Screening
mammography is the only effective screening technique for the early detection of clinically inapparent breast lesions
age: between the ages of 20 and 39 years, average risk women should undergo CBE every 3 years
after age 40 years CBE should take place annually, ideally prior to the women’s annual mammogram
