Principles of Chemotherapy Lecture PDF

Question 1

Colorectal is the __ most common cancer in men and women

Answer 1

colorectal

Question 2

Treatment of choice for disseminated cancers

Answer 2

Chemotherapy (drug therapy)

Question 3

4 major classes of anticancer agents

Answer 3

• cytotoxic agents (don’t have selective toxicity and kill all cells)
• hormones and hormone antagonists
• immunomodulators
• targeted drugs (bind specific molecules)

Question 4

Cancer cells and telomerase activity

Answer 4

Normal cells see telomere shortening upon division, however cancer cells have extremely active telomerase which preserves their telomeres allowing them to divide indefinetly

Question 5

What is a major determinant of a tissue’s responsiveness to chemotherapy?

Answer 5

Growth fraction - the ratio of proliferating cells to G0 cells

Question 6

Anticancer agents rae more active against cells with a high or low growth fraction?

Answer 6

High (disseminated cancers such as leukemia and lymphoma) compared to low (solid tumors, respond poorly)

Question 7

Chemotherapy drug dosing

Answer 7

With each successive round dosage must remain the same even though cancer is getting progressively smaller, patient must tolerate same degree of toxicity late in therapy as when began which is often not possible

Question 8

Complete remission

Answer 8

When all signs of disease are absent and cancer has reduced to less than 1 million cells leaving it virtually undetectable - not obvious how long chemo should last, no objective means of determining when to discontinue use

Question 9

Large tumors are less responsive to chemotherapeutic agents. Why?

Answer 9

As tumor increases size, many cells leave cycle and enter G0 causing growth fraction to decline - this growth slows because blood flow to the core of the tumor is low depriving cells of oxygen and nutrients

Question 10

Tumor growth curve (gompertzian kineetics)

Answer 10

Growth fraction begins very high with short doubling time before eventually leveling off at a certain size

Question 11

Debulking

Answer 11

Process of enhancing drug sensitivity of solid tumor by reducing solid tumor in size by surgery or irradiation causing many remaining cells to leave G0 and re enter cell cycle increasing sensitivity to chemo

Question 12

P glycoprotein synthesis in cancer cells

Answer 12

One of the mechanisms of resistance to anticancer drugs seen in cancer cells, can bring about multi drug resistance thru pumping out anticancer drugs resulting in cross resistance to many structurally unrelated drugs

Question 13

Risk of drug resistant cells development over the course of chemotherapy

Answer 13

Risk of therapeutic failure becomes greater with each course of therapy because tumor cells are heterogenous and contain many dissimilar cells

Question 14

Intermittent chemotherapy definition

Answer 14

Because the goal of chemo is to kill 100% of neoplastic cells with limited injury to normal tissues (esp. bone marrow and GI epithelium) the therapy is given on a schedule intermittently to allow for normal cells to repopulate faster than malignant cells (only way chemo will be effective) then dose again to progressively lower the amount of cancer

Question 15

Combination chemotherapy defintion

Answer 15

Use of combination of drugs for more effective therapy such as suppression of drug resistance, increased cancer cell kill, and reduced injury to normal cells with hopes of suppression of drug resistance

Question 16

Optimization of dosing schedules in cancer treatment

Answer 16

Many doses over a day is more efficient at killing more cells as they are in the S phase opposed to delivering a single large dose every few days at the same time

Question 17

Major toxicities of the anticancer drugs (which is the most serious?) (7)

Answer 17

• bone marrow suppression
• neutropenia (most serious can cause normally benign infections to kill)**
• thrombocytopenia (increased risk of serious bleeding, avoid anticoagulants)
• severe nausea and vomiting
• digestive tract injury
• diarrhea
• alopecia

Question 18

The nadir

Answer 18

The phase during anticancer treatment where which neutropenia reaches its lowest count (typically between days 10-14) that call urgent attention to minimizing contagion - employing colony stimulating factors can help mitigate this

Question 19

Anticipatory emesis and how is it treated?

Answer 19

A condition seen in patients undergoing chemo treatments where they experience nauea and vomiting before future visits, requires lorazapam (ativan) to reduce anxiety

Question 20

Reproductive toxicity of chemotherapeutic agents

Answer 20

-women should not get pregnant on chemo, may need to terminate pregnancy, drug effects on ovaries can result in amenorrhea, menopausal symptoms, and atrophy of vaginal epithelium as well as irreversible sterility in men

Question 21

Karnofsky performance scale

Answer 21

A scale that can predict the outcomes of chemotherapy treatment out of 100 (best) and <40 being severely debilitated having a hard time with chemo)