Cancer Chemotherapy.

Question 1

chemotherapy

Answer 1

the use of chemical agents to stop cancer cells from growing and hopefully kill the cancer - can eliminate cancer cells at sites distant form the original cancer

Question 2

When is chemotherapy used?

Answer 2

indicated for cancers that are not amenable to surgery or radiation therapy - also used as a supplemental treatment to prevent metastasis following surgery/radiation

Question 3

What are the advantages of drug combinations?

Answer 3

1. provide maximal cell killing within the range of tolerated toxicity 2. effective against heterogeneous cell populations in tumors 3. reduce the chance of development of resistant clones

Question 4

What are the successful combination regimens?

Answer 4

ABVD: doxorubicin (adriamycin), bleomycin, vinblastine, dacarbazine CHOP: cyclophosphamide, hydroxydoxorubicin, vincristine (oncovine), prednison MOPP: mechlorethamine, vincristine (oncovine), procarbazine, prednisone CMF: cyclophosphamide, methotrexate, 5-fluorouracil FEC: 5-fluorouracil, epirubicin, cyclophosphamide

Question 5

What are limitations of cancer chemotherapy?

Answer 5

drug resistance (some inherent, some acquired) and toxicity (affect normal cells undergoing rapid proliferation)

Question 6

What are mechanisms of drug resistance?

Answer 6

1. decreased cellular uptake 2. abnormal transport f drug (P-glycoprotein) 3. increased cellular inactivation (binding/metabolism) 4. altered target protein 5. reduced affinity for the drug 6. enhanced repair of DNA damage

Question 7

What are the seven classes of anticancer drugs?

Answer 7

1. alkylating agents 2. antimetabolites 3. DNA intercalating agents 4. Microtubule inhibitors 5. topoisomerase inhibitors 6. hormones and their antagonist 7. miscellaneous agents

Question 8

What is multidrug resistance most likely due to?

Answer 8

increased expression of cell surface glycoproteins - especially P-glycoprotein involved in drug efflux

Question 9

P-glycoprotein

Answer 9

use ATP to drive drug molecules out of cancer cells

Question 10

What drug inhibits drug transporters (esp. P-glycoprotein)

Answer 10

verapamil (Ca2+ channel antagonist)