Chapter 101: Basic Principles of Cancer Chemotherapy

A patient who has undergone surgical removal of a solid tumor has just begun chemotherapy. The patient experiences severe nausea and vomiting as well as alopecia. The nurse will expect the provider to: a.continue the chemotherapeutic agent at the same dose. b.decrease the dose of chemotherapy to minimize side effects. c.order lab tests to evaluate for the presence of residual cancer cells. d.stop the chemotherapy because the tumor has been removed.

ANS: A Cure of cancer requires 100% cell kill. Solid tumors, which often respond poorly to chemotherapeutic agents, can be "debulked" with surgery and then treated with cytotoxic drugs, because the remaining cells often re-enter the cell cycle and become sensitive to the drugs. Chemotherapeutic drugs must be given at the same dose throughout therapy because of the kinetics of drug-induced cell kill. Because chemotherapy has just begun, it is still necessary; moreover, cell counts of fewer than 1 billion cells are no longer detectable and treatment must continue until all cells are eradicated, so lab tests will not yield useful information. Stopping the chemotherapy right after surgery is not indicated.

A nurse is teaching a group of nursing students about how cytotoxic anticancer drugs affect normal cells. Which statement by a student indicates an understanding of this teaching? a."Cytotoxic drugs lack tissue specificity." b."Cytotoxic drugs have a high degree of selective toxicity." c."Differences between cancer cells and normal cells are qualitative." d."Neoplastic cells and normal tissue cells are very different."

ANS: A Cytotoxic drugs kill target cells as well as normal cells, since they lack specificity for cancer cells alone. Cytotoxic drugs therefore have a low degree of selective toxicity. The differences between cancer cells and normal cells are quantitative and not qualitative. Neoplastic cells and normal cells are very similar.

A patient with cancer who is receiving chemotherapy develops a fever. The patient's chest radiograph is normal. The patient's neutrophil count is 750/mm3. The nurse expects the provider to: a.begin empiric therapy with intravenous antibiotics. b.obtain cultures and wait for results before prescribing antibiotics. c.order colony-stimulating factor to minimize neutrophilia. d.reassure the patient that serious infection is unlikely.

ANS: A In the absence of neutrophils, as occurs with bone marrow suppression in chemotherapy, fever is the principle sign of infection. Pus, abscesses, and infiltrates on a chest x-ray may all be absent. When a neutropenic patient develops an infection, immediate and vigorous intervention is required. Empiric IV antibiotic therapy should begin while waiting for laboratory results and cultures. It is not correct to wait for culture results before initiating antibiotic therapy. Colony-stimulating factor can minimize neutropenia but does not eliminate the need for IV antibiotics. It is not correct to reassure the patient that a serious infection is unlikely.

A nursing student asks a nurse why chemotherapeutic agents are given intermittently instead of continuously. The nurse will tell the student that intermittent dosing: a.allows normal cells to recover and repopulate. b.catches malignant cells in latent phases. c.increases cancer cell kill and speeds up treatment. d.suppresses drug resistance in tumor cells.

ANS: A Intermittent chemotherapy allows normal cells to repopulate between rounds of therapy. Cells in latent phases do not generally respond to chemotherapy. Intermittent therapy does not speed up treatment or increase tumor cell kill. Intermittent therapy does not suppress drug resistance in tumor cells.

A patient asks a nurse about ways to minimize side effects of chemotherapy. Which response is correct? a."Avoid contact with people who are ill." b."Take antiemetics immediately after receiving chemotherapy." c."Treat fevers immediately with ibuprofen." d."Use a firm-bristled toothbrush to stimulate gums."

ANS: A Patients receiving chemotherapy should be taught to avoid contact with people who are ill in order to minimize their chances of contracting an illness, which could be devastating if they are neutropenic. Antiemetics are useful when given before chemotherapy. Fevers need to be investigated; taking antipyretics can mask fever, which is often the only indication of an infection. A firm-bristled toothbrush can further irritate gums; good oral hygiene is necessary, but with a soft-bristled brush.

What contributes to drug resistance to chemotherapeutic agents? (Select all that apply.) a.Cellular production of P-glycoprotein b.Creation of selection pressure by drugs c.Drug-induced cellular mutation d.Increased drug uptake by tumor cells e.Reduced target molecule sensitivity

ANS: A, B, E Drug resistance can occur by cellular production of a drug transport molecule, known as P-glycoprotein, that can transport the drug out of the cell; creation of selection pressure by favoring drug-resistant mutant cells; and reduction of target molecule sensitivity. Drug resistance does not occur by drug-induced mutation or increased drug uptake by tumor cells.

Which are guidelines for selecting chemotherapeutic agents to use in combination therapy? (Select all that apply.) a.Drugs used should have different mechanisms. b.Each drug should be delivered by different routes. c.Each drug should be effective. d.Each drug should have different dosing schedules. e.Toxicities should be minimally overlapping.

ANS: A, C, E When selecting drugs for combination therapy, each drug should be effective by itself and should have a different mechanism of action. The drugs should have minimally overlapping toxicities. The routes and the dosing schedules are not considerations.

A patient who has leukemia is receiving chemotherapy and develops severe anemia. The provider has ordered hospitalization and blood transfusions. The patient asks the nurse about using erythropoietin (epoetin alfa) instead. What will the nurse tell this patient? a."Ask your provider about ordering erythropoietin instead of a transfusion." b."Erythropoietin (epoetin alfa) can make your leukemia worse." c."Erythropoietin is used to prolong life in patients with myeloid malignancies." d."You will probably receive erythropoietin along with the transfusion."

ANS: B Erythropoietin is used to stimulate erythrocyte production but can also stimulate proliferation of cancers in patients with leukemia and other myeloid malignancies. It is used when the goal is palliation, not to cure or to prolong life.

A patient is receiving chemotherapy. Seven days after a dose, the patient's neutrophil count is 1000 cells/mm3. The nurse will tell this patient: a.that hospitalization is necessary to provide infection prophylaxis. b.that the provider will probably repeat the lab work in 3 to 5 days. c.to ask the provider about skipping the next dose of chemotherapy. d.to report any symptoms such as pus, abscesses, or cough.

ANS: B Normal neutrophil counts range from 2500 to 7000 cells/mm3. The lowest neutrophil count, or nadir, usually occurs 10 to 14 days after dosing, so this patient's neutrophil count should be repeated at that time. Hospitalization is controversial because of the risk of exposure to serious infections. The next dose should not be skipped unless the neutrophil count is below 500/mm3. Patients with neutropenia may not have symptoms of pus, abscess, or cough and should be instructed to report any fever.

A hospitalized patient with cancer is receiving chemotherapy and reports oral pain. Inspection of this patient's oral mucosa reveals erythema and inflammation without denudation or ulceration. The nurse understands that: a.chemotherapy will have to be stopped until healing of the oral mucosa occurs. b.the patient can use a mouthwash with a topical anesthetic to control pain. c.the patient will need an antifungal agent to treat Candida albicans. d.the patient will need systemic opioids to control discomfort.

ANS: B Patients with mild stomatitis can use a mouthwash with a local anesthetic to control pain. Chemotherapy does not have to be stopped until the pain or ulceration is severe. Antifungal agents may be used to treat Candida albicans; this patient does not exhibit signs of that infection. Systemic opioids may be used when pain becomes severe.

These patients are receiving chemotherapy. Which patient should the nurse see first? a.The patient with lightly bleeding gums b.The patient with nausea and vomiting c.The patient with a fever of 100.3°F d.The patient with diarrhea and stomatitis

ANS: C Fever is the principal early sign of infection, which can have extremely serious implications for an immunosuppressed patient. Because of a lack of neutrophils as a result of chemotherapy, signs of infection may be masked. Lightly bleeding gums, nausea, and vomiting are to be expected in patients receiving chemotherapy. Diarrhea and stomatitis also are common in patients receiving chemotherapy.

A nurse explains to a patient with cancer why it is difficult to achieve 100% cell kill to cure cancer with chemotherapy. Which statement by the patient indicates a need for further teaching? a."It is necessary to continue giving the same dose of chemotherapeutic agents throughout therapy, even if toxicity occurs." b."Symptoms of cancer often disappear before all malignant cells are eradicated." c."The immune system attacks chemotherapeutic agents and renders them impotent." d."The immune system often fails to recognize cancer cells as foreign."

ANS: C The immune system does not attack chemotherapeutic agents, so this statement would indicate a need for further teaching. The same dose of chemotherapeutic agents must be given throughout therapy, which becomes difficult when patients have severe toxic reactions. Because cancer symptoms often disappear before all cells are killed, some therapies are stopped prematurely. The immune system does not recognize cancer cells as foreign and thus does not assist in cell kill.

The nurse wants to evaluate a nursing student's understanding of chemotherapy. The nurse asks, "Which factor would be a major obstacle to successful chemotherapy?" What is the student's best response? a."The patient's reluctance about the doses administered." b."The patient's degree of nausea." c."The toxicity of anticancer drugs to normal tissues." d."The difficulty attaining and maintaining venous access.

ANS: C The major obstacle to successful chemotherapy is the toxicity of anticancer drugs to normal tissues. The patient's reluctance regarding the dose is a vague response. The patient's degree of nausea should not be an issue, because many good antiemetics may be given prophylactically. The question does not address whether the chemotherapy is administered PO or IV; therefore, the response regarding venous access would be an assumption.

A patient with cancer has a tumor composed mostly of G0 cells. When teaching this patient about the disease, the nurse will make which statement? a."Cells in this patient's type of tumor will proliferate rapidly." b."Chemotherapeutic agents that are not toxic to other tissues may be used." c."This type of tumor is especially sensitive to chemotherapy." d."This tumor will be managed primarily with surgery."

ANS: D Cells in the G0 phase are mitotically dormant; tumors composed mostly of G0 cells have low growth fractions. Because cytotoxic agents are more active against tumors with high growth fraction, this patient's type of tumor will be managed primarily by surgery and not chemotherapy. Cells in this type of tumor do not proliferate rapidly.

A patient has just been diagnosed with cancer and will begin chemotherapy. The patient asks the nurse about the possibility of nausea and vomiting. The nurse will tell the patient that: a.nausea and vomiting can be avoided by having a snack before chemotherapy. b.nausea and vomiting are common side effects and will abate over time. c.nausea and vomiting are common and will be treated with antiemetics when they occur. d.the provider will order drugs to help prevent nausea and vomiting before each dose.

ANS: D Nausea and vomiting are common but can be reduced by premedication with antiemetics. Having a snack before dosing is not effective. This side effect will not abate over time. Antiemetics are most effective when given before dosing, not as needed.

A nurse is teaching a group of nursing students about cancer treatment. Which statement by a student indicates an understanding of the characteristics of cancer cells? a."Cancer cells are characterized by unrestrained growth and division." b."Division of cancer cells is characteristically rapid." c."Malignant cells of solid tumors do not invade other tissues." d."Telomerase is an enzyme produced by cancer cells that promotes metastases."

ANS: A Because malignant cells are unresponsive to the feedback mechanisms that regulate cellular proliferation in healthy tissue, they are characterized by unrestrained growth and division. Division of tumor cells is not necessarily rapid. Malignant cells of all types can metastasize. Telomerase is an enzyme that permits repeated division of cancer cells.