Intro to Cancer Biology/Chemotherapy Flashcards
What is metastasis? How is it aided?
the spread of cancer cells from a primary site to distant secondary sites, and it is aided by the production of enzymes on the surface of the cancer cell
In cancer, What does level of differentiation refer to?
the extent to which cancer cells resemble similar normal cells. Cells that are more mature, and more closely resemble their host cells are well-differentiated. Cells that grow rapidly and do not have the original tissues morphologic characteristics and cell functions are very dissimilar to their host cells are UNdifferentiated. They are typically more aggressive.
What is paraneoplastic syndrome?
When the patient exhibits signs and symptoms not directly related to the local effects of the tumor. This occurs when cancer cells inappropriately secrete hormones in an organ or tissue that does not normally produce or release those hormones. EX: small cell carcinoma of the lung causes increased production of ADH, resulting in hyponatremia
What role does proliferation play in the development of cancer?
In the normal cell cycle, the need for renewal replacement stimulates cell proliferation. When this stimulus is cone, cell production stops, which produces balance between cell production and cell loss. In Cancer, proliferation starts once the stimulus is initiated, but then also CONTINUES in uncontrolled growth, because normal control mechanisms fail to stop this proliferation. These genetically unstable cells multiply, and become increasingly malignant as the cancer continues to proliferate
What is the Gompertzian growth curve?
a curve that demonstrates the trajectory of tumor growth. We see rapid, exponential proliferation of cancer cells initially, followed by continuous but slower growth. This is because as tumors grow in size, they require more oxygen and nutrients to continue proliferating. The body does not provide increased nutrients to these tumors, so we see smaller fractions of these tumors actually proliferating until they become necrotic and stagnant.
What is the difference between proto-oncogenes and oncogenes?
proto-oncogenes are nomal cells that regulate cell growth. Onco-genes are altered proto-oncogenes that promote autonomous cell growth in cancer cells, resulting in growth self-sufficiency
What is a complete carcinogen?
cancer-causing agents that have the ability to both initiate AND promote malignant transformation EX: cigarette smoke
How does “growth fraction” impact the doubling time of a tumor?
growth fraction refers to the ratio of the total number of tumor cells to the number of dividing cells. Larger growth fraction means quicker tumor growth. As tumor volume increases, growth fraction decreases d/t hypoxia and decreased availability of nutrients for the large tumor. Therefore, small and smaller numbers of tumor cells are actually able to actively divide.
What is tumor burden? What does increased tumor burden mean in terms of treatment?
the actual number of cells present in the tumor
*As tumor burden increases, growth rate decrease because number of cells actively dividing decreases
What does it matter if the tumor burden is highly heterogenous?
It means that the tumor is poorly differentiated, and is made up of many unorganized cells, meaning that there is a higher likelihood of the creation of drug resistent clones
What is serosal seeding?
local invasion when tumors which have invaded a body cavity from surrounding tissue, attach to the surface of an organ within that cavity. EX: attach to the stomach through invasion of the peritoneal cavity
How are the lymphatic system and the circulatory system interconnected?
the main lymphatic trunk enters the venous system just before the veins enter the heart, which means that cancer cells that enter the lymphatic system are also able to enter the bloodstream
Describe hematological spread of cancer
tumor cells follow the venous flow that drains the site of the neoplasm. EX: venous blood from the GI tract, pancreas and spleen is routed through the portal vein of the liver before entering the circulation. Therefore, the liver is a common metastatic site for cancers that originate in these organs.
Explain the TNM staging system
T refers to the size of the primary tumor
N refers to regional lymph node involvement
M refers to distant metastasis
What does the “Grade” of cancer refer to?
grade refers to the level of differentiation of cancer cells. G1 is well differentiated, meaning less aggressive, easier to treat. G4 is undifferentiated, meaning more aggressive and more difficult to treat.
