WITH ANSWERS RATED A+
✔✔ Doubling time - ✔✔ The time required for a tumor mass to reach a certain size or
double in size.
✔✔ Growth fraction - ✔✔Percentage of cells actively dividing at any given point in time.
✔✔ Tumor burden - ✔✔Size of the tumor as determined by the number of cells present.
✔✔ A higher growth fraction - ✔✔ Results in a higher cell kill with exposure to cell cycle
specific agents.
✔✔ The higher the tumor cell burden - ✔✔The greater the probability of the
development of drug resistance
✔✔ Gompertzian function - ✔✔ As the tumor burden increases, the rate of growth slows
or levels off.
✔✔ 6 essential alterations in normal cell physiology that dictate malignant growth - ✔✔ 1.
Self-sufficiency in growth signals 2. Insensitivity to growth-inhibitory signals 3.
Avoidance of apoptosis 4. Limitless replication potential 5. Sustained antiangiogenesis
6. Tissue invasion and metastasis
✔✔ 6 cell characteristics of malignant cells in easier terms - ✔✔ Mutated DNA alters
instructions for function 2. Parasitic to host and has no beneficial function 3.
Uncontrolled reproduction 4. Invades surrounding tissues and mets 5. Immortal 6. Call
birth is greater then cell death
✔✔ 6 mechanisms of drug resistance by the cell - ✔✔ 1. Decreased drug uptake by the
cell 2. Increased removal of the drug out of the cell r/t changes in the cell membrane 3.
Detoxification of the drug in the cell r/t metabolic changes 4. Increased repair of DNA 5.
Alterations in the structure of drug receptor sites 6. Decreased sensitivity to apoptosis.
✔✔ MDR1 - ✔✔ Multidrug resistance gene 1. May occur prior to exposure of chemo or
after. Caused by the presence of P-glycoprotein
✔✔ How should chemo be administered to maximize effectiveness? - ✔✔ At the
maximum tolerated doses with the shortest possible interval
✔✔What are chemotherapy effects on the cell cycle with cell cycle specific drugs? -
✔✔ 1. Greatest effect on actively dividing cells 2. NOT active in G0 phase 3. Greatest
action in divided doses or continuous infusion 4. Cytotoxic effects occur when cell repair
or division is attmepted