By Dr Ananya Mandal, MD
Over the last few decades with the advent of new medications and therapeutic approaches, treatment of leukemias has become largely improved with better survival rates and lesser treatment-related adverse effects.
Despite advances some people respond better to therapy than others. The subtype of acute myeloid leukemia plays a huge role in determining the possible outlook or prognosis of the cancer.
There are several other factors that determine the possible outlook of patients with AML.
Some of the prognostic factors include:-
Test results from cytogenetic assays and chromosomal abnormalities. Some of the chromosomal abnormalities predict a good and favourable outcome. These include translocation between chromosomes 8 and 21 (seen most often in patients with M2), translocation between chromosomes 15 and 17 (seen most often in patients with M3) and inversion of chromosome 16 (seen most often in patients with M4). Unfavorable abnormalities include deletion or loss of part of chromosome 5 or 7 (no specific AML type) and complex changes involving several chromosomes. Around one third of all AML patients also have mutation in the FLT3 gene. These people tend to have a poorer outcome. However, there are drugs that target this defective gene. People with changes in the NPM1 gene have a good prognosis.
Presence of pre-existing blood disorders such as myelodysplastic syndrome.
History of treatment with chemotherapy and/or radiation therapy for an earlier cancer.
Older patients over the age of 60 usually have a poorer outcome than young patients. Older patients may also have other medical conditions that make treatment with chemotherapy difficult.
A high white blood cell count (>100,000) at the time of diagnosis is associated with a bad prognosis.
Those with an active systemic or blood infection at the time of diagnosis usually fare worse than those who do not have such infections.
Spread of the leukemia to the central nervous system, brain and spinal cord makes treatment difficult and thus predicts a poor outcome of the cancer.
A remission is defined as having no evidence of disease after treatment. This means the bone marrow contains fewer than 5% blast cells and normal blood counts. A molecular complete remission means there is no evidence of leukemia cells in the bone marrow with PCR and flow cytometry. Those patients who achieve remission after initial 4 weeks of therapy have a better prognosis than those who do not.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Nov 17, 2013