Precipitating exposures:
(1) radiation therapy
(2) chemotherapy
(2a) with alkylating agents
(2b) topoisomerase II inhibitors (etoposide, teniposide, doxorubicin, 4-epi-doxorubicin)
Features of AML following alkylating agents or radiation therapy:
(1) latency period 5-6 years (range 10 to 192 months)
(2) The risk is related to the total cumulative dose of the agent and the age of the patient.
(3) Usually preceded by myelodysplasia with multilineage dysplasia.
(4) Clonal cytogenetic abnormalities are common.
(5) The prognosis is often refractory to therapy and has a short survival. This appears to be associated with unbalanced cytogenetic abnormalities.
Features of AML following topoisomerase II inhibitor therapy:
(1) latency period 2-3 years (range 12 to 130 months)
(2) Usually preceded by a myelodysplasia syndrome, often with abnormal proliferation of monocytes.
(3) Clonal cytogenetic abnormalities are common, including t(9;11), t(11;19), t(6; 11).
(4) The prognosis appears similar to that of a de novo leukemia of the same type, but long term followup data is limited. The presence of balanced cytogenetic abnormalities may be associated with a better response to therapy.
