Flashcards in Exam 1 Deck (59):
What is Cancer?
A disease of cells involving dynamic changes (i.e. mutations) in the genome leading to loss of the normal control mechanisms that govern Proliferation, Differentiation, & Programmed death (apoptosis)
NOT always faster than normal cells, uncontrolled
Dedifferentiation (different degree); lost differentiation
Programmed death (apoptosis)
resistant to apoptosis
Undifferentiated cancer cells
Poorly differentiated (immature) , they do not differentiate into mature specialized cells, they remain immature-looking.
malignant transformation; multi-step process: initiation, promotion, and progression
Penetrating the muscle and get into circulation
Get out of vessel and relocate to a new home and form a new mass
Structural difference: Cancer Cells
Carry mutations including abnormal gene structure or numbers of chromosomes
Continue to be created without control or order. A Mass of tissue or tumor is formed
Differences in Energy Use: Normal Cells
70% of their energy from the Krebs cycle
Only 20% of their energy from glycolysis
Difference in Energy Use: Cancer Cells
Have a defective Krebs cycle and derive little or no energy from it.
Almost all their energy from glycolysis
Glycolysis even in the presence of oxygen (aerobic glycolysis)
High aerobic glycolysis by malignant tumors is utilized to?
diagnose and monitor treatment responses of cancers by imaging uptake of 2-18F-2-deoxyglucose (a radioactive modified hexokinase substrate) with positron emission tomography (PET)
Differences in Blood Vessels: Normal Cells
Have a built-in blood vessel system
Differences in Blood Vessels: Cancer Cells
Do not have a built-in blood vessel system. They require some chemical stimulation to build one, because tumor growth depends on development of new blood supply (i.e., angiogenesis).
Differences in Growth Factors: Cancer Cells
Overproduce growth factors.
Cells are overactive
Functional Differences: Cancer Cells
The enzymes and hormones are either overactive or underactive
From epithelial cells (line some organs and skin).
From connective or other deeper tissues.
Cancer of the blood
Cancer of the lymphatic system
What does the term "solid tumor" distinguish between?
Distinguish between a localized mass of tissue (carcinoma, sarcoma, and lymphoma) and leukemia
Cancer staging systems does not apply to what type of cancer?
leukemia -because the blood is not localized
Cancer staging systems
describe how far cancer has spread anatomically (i.e. metastasis)
For solid tumors there are two staging systems:
1. The overall stage grouping system
2. The tumor, nodes, and metastases (TNM) system
This stage - Small localized cancers that are usually curable
Stages 0 and I
Stages II and III
Locally advanced and/or involvement of local lymph nodes.
Inoperable or metastatic cancer
Measure of how abnormal cells appear under the microscope
grade cannot be assessed (least aggressive)
undifferentiated (most aggressive and fast growing)
Associated with upper respiratory tract, lung, esophageal, bladder, and pancreatic cancers
Can cause cancer in upper GI tract by increasing permeability of mucosa to carcinogens.
Associated with hepatocellular carcinoma, pancreatic cancer, etc.
Skin cancer such as squamous and basal cell carcinoma and melanoma
Whitest skin, highest risk
Associated with development of leukemia and thyroid cancer
Foods associated with increased risk of developing cancer such as colon, prostate, and breast
high fat, high calories intake
salt cured, smoked or charred foods
nitrate and nitrite additives
Non-Hodgkin’s lymphoma and nasopharyngeal cancer
Kaposi’s sarcoma and lymphoma
Cutaneous T-cell lymphoma
Human papilloma virus
Hepatitis B virus
What are the two main categories of genetic changes that lead to cancer?
The activation of proto-oncogenes to oncogenes
The inactivation of tumor suppressor genes
Proto-oncogenes are normal genes whose protein products stimulate growth and viability of cells.
Also include genes that contribute to tumor growth by inhibiting cell death (inhibiting apoptosis)(“Do not die”)
Examples of Proto-Oncogenes
EGFR, HER2, BCL2
Oncogenes are mutated or damaged genes that contribute to tumor growth (oncogenes are defective proto-oncogenes)
Activation of proto-oncogenes
Mutation or amplification (increased #of gene copies); chromosome abnormality (“Driver mutations”)
Increase of protein expression
Tumor Suppressor Genes
Genes whose protein products can directly or indirectly prevent cell division or lead to cell death.
Inactivation of tumor suppressor genes
Mutation or deletion
Decrease of protein expression
the use of cytotoxic chemical agents to destroy cancer cells.
Most chemotherapy drugs interfere with
Cell growth cycle
Side effect profile of chemotherapy
Side effect profiles: hair follicles, bone marrow, skin, and the cells in GI tract (these are also fastest growing cells)