Acute myeloid leukemia, or AML, is a cancer of myeloid cells, which are a type of white blood cells, according to the American Cancer Society. Acute promyelocytic leukemia, or APL, is a specific subtype of acute myeloid leukemia and requires early treatment because of life-threatening bleeding and clotting complications associated with the cancer. As noted on the American Cancer Society website, remission can occur in about 70 to 90 percent of patients after treatment.
Anthracycline Chemotherapy
In adults, the first-line treatment for most patients with acute promyelocytic leukemia is an anthracycline-type chemotherapy drug such as daunorubicin or idarubicin, according to the American Cancer Society. This anthracycline drug is combined with all-trans retinoic acid; this combination can induce a remission in 80 to 90 percent of patients.
All-Trans Retinoic Acid
All-trans retinoic acid, or ATRA, is a medication that is in the vitamin A family and is used in both adults and children with acute promyelocytic leukemia. In adults, ATRA is combined with the anthracycline chemotherapy medication; in children, ATRA may sometimes be able to cause a remission when used alone, but the combination with the anthracycline gives a better long-term outcome, as noted on the American Cancer Society website. ATRA can also be used alone or in combination with other low-dose medications as a maintenance therapy for a year after the patient achieves remission. A side effect of ATRA is retinoic acid syndrome, with the symptoms of low blood pressure, difficulties breathing and kidney damage. Treatment involves discontinuing the medication and using a corticosteroid.
Low Dose Chemotherapy
During maintenance therapy, some physicians add low-dose chemotherapy to the ATRA treatments, according to the National Cancer Institute. Typically these particular chemotherapy drugs are 6-mercaptopurine and methotrexate in both children and adults.
Cytarabine
Another chemotherapy medication that may be combined with an anthracycline drug is cytarabine, according to NCI. The use of this medication in the regimen is still controversial and is not well-established in primary therapy.
Arsenic Trioxide
Arsenic trioxide can be used with ATRA in patients with acute promyelocytic leukemia who are unable to tolerate anthracycline chemotherapy, as noted on the American Cancer Society website. In newly diagnosed adults, the addition of arsenic to the treatment regimen resulted in improved outcomes in survival, according to NCI, which adds that children whose cancer has returned tolerate the arsenic trioxide medication very well. The most serious side effect of arsenic trioxide is an abnormal heartbeat.
Stem Cell Transplant
If the acute promyelocytic leukemia returns, some physicians will consider a stem cell transplant in selected patients. In both adults and children, a transplant is not generally considered after the first remission of the disease because of the success of the chemotherapy and ATRA regimen, according to NCI. However, if the disease returns and the chemotherapy/ATRA or other regimen successfully treats the leukemia, a stem cell transplant may be used in patients with appropriate donors.
