Acute myelogenous leukemia (AML), a cancer of immature blood cells, often responds well to chemotherapy. Drugs such as cytarabine and daunorubicin target cancer cells and can cause remission in the first phase of AML treatment (induction therapy). Chemotherapy can be used for the second phase (consolidation) to kill all remaining cancer cells, and in some patients chemotherapy can treat a relapse. New evidence shows that high doses of chemotherapy drugs in the induction phase give better results than the standard doses.
Chemotherapy Drugs
Chemotherapy drugs kill fast-growing cancer cells and some normal cells as well, causing common side effects like extreme fatigue, nausea and vomiting.
Compared to other forms of leukemia, AML has fewer options for chemotherapy. According to the Merck Manual, the standard drugs for AML chemotherapy are cytarabine, daunorubicin and idarubicin. Etoposide, vinicristine and thioguanine might be used in some cases.
Cytarabine and thioguanine mimic components of DNA, but their incorporation into DNA stops protein synthesis. Daunorubicin worms its way into the DNA helix, preventing its proper function. Etoposide and vinicristine prevent cellular reproduction.
Induction
According to the Merck Manual, the basic induction regimen for AML chemotherapy includes continuous intravenous infusion or high-dose injections of cytarabine for five to seven days, with intravenous daunorubicin or idarubicin in the first three days. These drugs massively suppress production of myeloid cells to stop the cancer, but they also leave the patient vulnerable to infections or bleeding episodes. Because of those concerns, patients remain in the hospital during chemotherapy for AML. If the first cycle does not induce remission, your doctor might recommend one to two additional cycles.
Consolidation
Oncologists often recommend chemotherapy for the consolidation phase of AML treatment as well. In the consolidation phase, you might undergo a more-intense regimen of higher doses of the same drugs used for induction, or your oncologist might want to try a different combination of drugs.
Relapse
If you suffer a relapse of AML, your oncologist might recommend another course of chemotherapy if you are young and had been in remission for at least a year. In those cases oncologists often combine chemotherapy with immunotherapy to increase effectiveness. Chemotherapy for relapse produces more severe side effects and does not work well in older patients or those who were in remission for less than a year.
Expert Insight
In 2008, a large clinical trial sponsored by the National Cancer Institute revealed that high-dose chemotherapy for AML promoted longer survival compared to survival of patients treated with the standard dose of the same drug. In this trial, a high dose of daunorubicin in the induction phase (90 mg/sq meter of body surface area) for the first three days of treatment gave patients an extra eight months of survival as compared to the standard dose (45 mg/sq meter of body surface area) for the first three days of treatment. The higher dose did not produce any extra side effects.
