Week 7 - Chapter 101 -Basic Principles of Cancer Chemotherapy

Question 1

Adjuvant Therapy

Answer 1

therapy that improves the benefit of another therapy, that other therapy would usually be called the “Primary Therapy.”
Example being chemotherapy after “removal” of a tumor. The debulking removes 90% of the tumor and the 10% remaining goes through recruitment (which involves rapid multiplication) which makes it more vulnerable to chemotherapy.

Question 2

Cell Cycle

Answer 2

Four phases of gene expression and cell biology that cells must progress through to complete cell division and proliferation

• G0- Resting
  1. G1- Synthesis of components for synthesis of DNA (getting ready for DNA synthesis)
  2. S - synthesis of DNA
  3. G2 - synthesis of components for Mitosis (getting ready for Mitosis)
  5. M- Mitosis
• Starts all over again.

Question 3

Debulking

Answer 3

Surgical Reduction of a tumor

Question 4

First-Order Kinetics

Answer 4

Given dose of drug will kill the same % cancer cells (e.g. 90%)
So you must use more and more drug to kill fewer and fewer cells (since it is a percentage, e.g. 1,000 cells you kill 900, 100 cells you kill 90; pay off is less but drug amount is the same)
But you need 100% cell kill, and can not rely on immune system!

Question 5

Gompertzian Kinetics

Answer 5

fast (drug sensitive) when too small to diagnose, slow (drug resistant) when large enough to diagnose.
Not all solid tumors are equally unresponsive: As a rule, large tumors are even less responsive than small ones. This difference occurs because, as solid tumors increase in size, more of their cells leave the cell cycle and enter G0, causing the growth fraction to decline even further. Tumor growth slows, in large part, because blood flow in the tumor core is low, depriving cells of nutrients and oxygen. The decrease in growth fraction in older tumors is a major reason why therapeutic success is more likely when cancers are detected early. Because the rate of growth declines as a tumor gets larger, the tumor growth curve is said to follow Gompertzian kinetics.

Question 6

Metastasis

Answer 6

Tumor spread into distant tissue, usually through bloodstream

Question 7

Oncogenes

Answer 7

A gene that, when overexpressed, encourages a cell to become cancerous

Question 8

Karnofsky Performance Scale

Answer 8

General health status is assessed by measuring performance status, frequently using the Karnofsky Performance Scale. A Karnofsky score of less than 40 indicates the patient is debilitated and not likely to tolerate the additional stress of chemotherapy. Accordingly, patients with a low Karnofsky rating should not receive anticancer drugs—unless their cancer is known to be especially responsive.
Measured by: able to carry on normal activity and work, . Under 40 means that the patient is unable to care for themselves.

Question 9

Telomerase

Answer 9

Telomerase is an enzyme that keeps the tips of chromosomes from losing their DNA during DNA replication/cell division. Normally this loss of chromosome tips would eventually cause cells to stop dividing.

Question 10

Nadir

Answer 10

Low point, “bottoming out” of a Neutropenic curve. This usually happens between days 10-14.
Patient care
Avoid opportunistic infections
Granulocyte colony‒stimulating factor (filgrastim), long-acting granulocyte colony‒stimulating factor (pegfilgrastim), and granulocyte-macrophage colony‒stimulating factor (sargramostim).

Question 11

“Myth” of Early Detection

Answer 11

There is really no early detection (except with cervical cancer because of PAP- smears). By the time that cancer is detectable there are already about 1 billion cancer cells in the body.

Question 12

Palliative Treatment

Answer 12

designed to relieve symptoms, and improve your quality of life.

Question 13

Persistent Proliferation

Answer 13

Unlike normal cells, whose proliferation is carefully controlled, cancer cells undergo unrestrained growth and division. This capacity for persistent proliferation is the most distinguishing property of malignant cells. In the absence of intervention, cancerous tissues will continue to grow until they cause death.

Question 14

P-glycoprotein

Answer 14

a large molecule that spans the cytoplasmic membrane and pumps drugs out of the cell. Induction of P-glycoprotein synthesis during exposure to a single anticancer drug produces cross-resistance to agents in other drug classes. Several drugs, including cyclosporine, have been used investigationally to inhibit the P-glycoprotein pump and reverse multiple drug resistance.

Question 15

Recruitment

Answer 15

When a solid tumor is reduced by surgery or irradiation, many of the remaining cells leave G0 and reenter the cell cycle, thereby increasing their sensitivity to chemotherapy.

Question 16

Remission

Answer 16

Once a cancer has been reduced to less than 1 billion cells, it becomes undetectable by usual clinical methods; all signs of disease are absent, and the patient is considered in complete remission. It is obvious, however, that a patient harboring a billion malignant cells is by no means cured. It is also obvious that further chemotherapy is indicated. However, what is not so obvious is just how long therapy should last: Because the patient is already asymptomatic, we have no 1210objective means of determining when to stop treatment. The clinical dilemma is this: If therapy continues too long, the patient will be needlessly exposed to serious toxicity; conversely, if drugs are discontinued prematurely, relapse will occur.

Question 17

Telomerase

Answer 17

Telomerase is an enzyme that keeps the tips of chromosomes from losing their DNA during DNA replication/cell division. Normally this loss of chromosome tips would eventually cause cells to stop dividing.

Question 18

Tumor Suppressor Gene

Answer 18

A gene whose expression works against a cell becoming cancerous

Question 19

Vesicant

Answer 19

Chemically reactive drug that damages tissues, often as a result of leaking out of an IV infusion/injection site.

Question 20

Bone Marrow Suppression

Answer 20

Reduces the number of circulating neutrophils, platelets, and erythrocytes
Loss of these cells has three major consequences:
Infection (from loss of neutrophils)
Bleeding (from loss of platelets)
Anemia (from loss of erythrocytes)

Question 21

Digestive Tract Injury

Answer 21

Stomatitis (inflammation of the oral mucosa)
Treatment of mild stomatitis: Mouthwash containing a topical anesthetic (for example, lidocaine) plus an antihistamine (for example, diphenhydramine)
Treatment of severe stomatitis: Systemic opioid
Diarrhea
Treatment: Oral loperamide

Question 22

Nausea/Vomiting in Chemotherapy

Answer 22

Cause: Chemo drugs activate Chemoreceptor Trigger Zone in Brain
Treatment: Premedication, Combinations of anti-emetics