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| AML |
AML
OAML also termed as acute non lymphoblastic leukemia accounts for 15-20% of childhood leukemia.AML is much more complex and resistant disease than acute lymphoalartic leukemia.progress has been slower therapy more complicated.but with intensive myelosuppressive induction and further post remission therapy abt 40% of such patients can now achieve long term survival and probably cure.Biology...
AML can be divided into several sub groups according to the french american british morphological classification system (M0 to M7).
M0-immature
M1-acute myeloblastic leukemia with minimal maturation
M2-acute myeloblastic leukemia with maturation
M3-acute promyelocytic leukemia
M4-acute myelomonocytic leukemia
M5-acute monoblastic leukemia
M6-erythroblastic L.
M7-acute megakaryoblastic L.
Abt 30-40% are M1 and M2.same %age of M4 and M5.M3 constitutes 5-10%.M7 strongly associated with downs syndrome.trans location between chromosome 8 and 21 is found almost exclusively in M1 and M2.all patients with M3 carry translocation t(15;17) and M5 is asso. With t(9;11).
Clinical presentation
Most patients with presents with pallor.fatigue.bleeding or fever as manifestations of their under lying anemia.thrombocytopenia and neutropenia as a result of bone marrow failure.unlike ALL,bulky lymphadenopathy and massive hepatosplenomegaly is not very common.however infants and toddlers may have more organomegly.high WBC count and CNS disease at diagnosis. They are mostly M4 and M5 sub types.
Disseminated intravascular coagulation may occur with any sub group but common in M3.
Chloromas are localised collections of leukemia cells seen almost exclusively in patients with AML.They may occur at any site including CNS, bones typically orbit and skin.gingival hyper trophy may be present.
Diagnosis must be confirmed by bone marrow exam.morphological cytochemical immunophenotypic and genetic characteristics of the leukemia blast should be determined if possible.sometimes the diagnosis is preceded by prolonged pre leukemia phase lasting several weeks or months.usually this is characterised by a lack of one of the normal blood cell lineages resulting in either a refractory anemia a moderate degree of neutropenia or thrombocytopenia.the condition is often referred to as myelodysplastic syndrome.some children may be seen with hypo plastic marrow that may develop later into an acute leukemia.
Treatment
The main drug used for induction therapy are combination of cytosine arabinose and an anthracycline(doxorubicin or daunorubicin).the induction regimen most commonly used is 100 mg/m2/day of cytosine given as continuous infusion for 7 days plus daunomycin at 45 mg/m2/daw for 3 days with or without additional drugs.other drugs like etoposide n thioguanine have been added.with the current regimen remission could be induced in about 70 to 80% of children.however without further therapy most children relapse within 1 year.
Post remission therapy include high ford chemo therapy hocke Ara C and etoposide or bone marrow trans plantation.
allogenic bone marrow trans. is superior to intensive chemo therapy alone.
The subset acute pro myelocytic L. which accounts for about 10-15% of children with AML should be treated separately.best therapy to induce remission by All transretinoic acid as a single agent and then the remission is consolidated with post remission intensive chemo therapy.
Children also require platelets and broad spectrum antibiotics for control of severe infections.
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